Endolumenal aortic isolation assembly and method

ABSTRACT

A medical device system and method allows an arterial bypass graft to be proximally anastomosed to an aorta during a beating heart procedure without substantial loss of blood by use of an endolumenal aorta isolation assembly provided along the distal end portion of an elongate catheter body. The aorta isolation assembly includes proximal and distal portions that are separated by an isolation region and that are adjustable to first and second extended positions, respectively, which are adapted to circumferentially engage the aortic wall and isolate upstream and downstream aspects of an exterior space between the elongate body and the aortic wall. The intermediate region is adapted to be positioned along the proximal anastomosis site such that the distal and proximal portions when adjusted to the first and second extended positions circumferentially engage the aortic wall on upstream and downstream sides of the proximal anastomosis site. Blood flowing within the aorta is thereby isolated from the proximal anastomosis site along the intermediate region and is shunted from an upstream region of the aorta, through the distal port into the flow lumen, proximally along the flow lumen, out from the flow lumen through the proximal port. The assembly may also be used in a “stopped heart” cardiac bypass procedure, wherein a cannula having an expandable valve may be selectively positioned in the internal flow lumen along the elongate body between the distal and first proximal ports and is adjustable from an open position, wherein the flow lumen is open between the distal and first proximal ports, to a closed position, wherein the flow lumen is substantially closed between the distal and first proximal ports. By positioning the expandable valve between the first proximal port and a second proximal port along the proximal end of the elongate body and adjusting the expandable valve to a closed position the flow lumen is substantially closed between the first and second proximal ports.

[0001] This application is a continuation-in-part of application Ser.No. 09/191,260 filed Nov. 12, 1998 which was a continuation-in-part ofapplication Ser. No. 09/976,250, filed Nov. 21, 1997.

TECHNICAL FIELD

[0002] The present invention is a surgical device assembly. Moreparticularly, it is a medical device system and method for endolumenallyisolating a region of a patient's aorta from the patient's systemicarterial circulation so that surgery may be performed on the isolatedportion of the aorta or the patient's heart.

BACKGROUND

[0003] Conventional “Cardiac Bypass” Procedures

[0004] Various medical procedures have been developed for treatingparticular abnormalities of the heart and vascular system at least inpart by temporarily arresting the heart from beating, isolating theheart from systemic blood circulation, supporting the systemic bloodcirculation via an external cardiopulmonary bypass pump, and performingsurgical operations directly on the stopped heart. This general methodis herein referred to interchangeably as a “cardiac bypass” or“cardiopulmonary bypass” procedure. Examples of more particular surgicaltreatments which use such cardiac bypass procedures include, withoutlimitation: coronary artery bypass graft surgery (“CABG”); valvereplacement surgery; cardiac transplantation surgery; and a procedureknown as the “maze” procedure wherein conduction blocks are surgicallyformed in the wall of one or both of the atria in order to preventatrial fibrillation.

[0005] Conventional techniques for performing such “cardiac bypassprocedures” generally cutting through the sternum in the chest cavityusing well known “sternotomy” techniques, spreading open the rib cage,retracting the lungs from the region of the heart, and directly exposingthe heart to the surgeon. One of various known cardioplegia agents maybe used to temporarily arrest the heart from beating. Further to thebypass procedure, an external cross clamp is generally used to occludethe aorta in the region of the arch between the aortic root and thecarotid arteries. With the cross-clamp in this position, both the leftheart chambers and the coronary arteries into the heart are isolatedfrom the systemic arterial circulation while the carotid arteries arefed with the blood flow from the bypass pump. In addition, flow from thesuperior and inferior vena cava is also temporarily diverted from theheart to the pump, usually by externally tying the vena caval walls ontovenous pump cannulae. Such conventional cardiac bypass procedures asjust describe which involve performing a sternotomy are hereafterreferred to interchangeably as “open chest” or “open heart” procedures.

Minimally Invasive Cardiac Bypass Catheter Systems

[0006] Recent advances have been made in the field of “cardiac bypassprocedures” which include the use of novel catheter assemblies which areadapted to temporarily arrest and bypass the heart without the need fordirect cross-clamping or externally tying the vena cavae. Suchassemblies are generally herein referred to by the terms “minimallyinvasive catheter bypass systems,” or derivatives of these terms, andgenerally include an arterial catheter, which isolates the left heartchambers from systemic arterial circulation beyond the aortic root, anda venous catheter, which isolates the right heart chambers from venouscirculation from the vena cavae. Further to the intended meaning, suchminimally invasive catheter bypass systems may be used during open chestprocedures requiring a sternotomy, as well as during other cardiacbypass procedures which otherwise alleviate the need for suchsternotomies, such as for example procedures known as “port access”procedures.

[0007] One particular example of a previously known “minimally invasivecardiac bypass system” uses an arterial catheter which occludes theaorta from systemic arterial circulation with an inflatable balloonlocated on the outside surface of the catheter's distal end portionwhich is positioned within the aorta. The arterial catheter furtherincludes a cannula with lumens and distal ports which provide forcardioplegia agent delivery and venting of the left ventricle,respectively, while the heart is isolated from systemic circulation withthe inflated balloon on the outer surface of the arterial catheter.Further to this known system, a venous catheter is further provided anduses a balloon in each of the superior and inferior vena cava. Thevenous catheter balloons inflate to occlude these great veins andthereby isolate the right heart chambers from systemic venous bloodflow. Moreover, the venous and arterial catheters which combine to formminimally invasive cardiac bypass catheter systems engage to inlet andoutlet ports, respectively of a cardiopulmonary bypass pump, which pumpmay be further considered a part of the overall system. One such knownpump which is believed to be particularly useful in cardiac bypassprocedures, including minimally invasive bypass procedures, is known asthe “BioPump”, Model Number “BP80”, which is available from Medtronic,Inc.

[0008] Further to the description for the minimally invasive cardiacbypass system example just provided above, the terms “proximal” and“distal” are herein used throughout this disclosure as relative terms.In the context of describing a device or catheter used in such a system,the term “proximal,” such as in the phrase “proximal end”, is hereinintended to mean toward or closer to a user such as a physician, whereasthe term “distal,” such as in the phrase “distal end” is herein intendedto mean away from or further away from the user. However, if and wherethe terms “proximal” and “distal” are herein used in the context ofdescribing anatomical structures of the cardiovascular system orphysiological blood flow, the term “proximal” is herein intended to meantoward or closer to the heart, whereas the term “distal” is hereinintended to mean away from or further from the heart. Furthermore, theterms “upstream” and “downstream” are also relative terms which may beherein used interchangeably with “proximal” or “distal”, respectively,in the anatomical or physiological context just described.

[0009] According to the known minimally invasive cardiac bypass cathetersystems and methods, the heart is usually put on “partial bypass” priorto “complete bypass”. The terms “partial bypass” are herein intended tomean a condition wherein the heart is beating and pumping bloodthroughout the body's circulation prior to inflating the balloons on thearterial and venous catheters, and wherein some blood is also aspiratedfrom the vena cavae through the venous catheter, sent through thecardiopulmonary bypass pump, and infused into the arterial circulationthrough the flow ports along the arterial catheter. The terms “completebypass” or “full bypass” or derivatives thereof are therefore hereinintended to mean a condition wherein the heart is substantially isolatedfrom systemic venous and arterial circulation by means provided by thevenous and arterial catheters, respectively, such as for example byinflating balloons on the exterior surfaces of such venous and arterialcatheters to thereby totally occlude the vena cavae and aorta, alsorespectively, as described above.

[0010] According to these definitions for partial and full bypass justprovided, a patient is therefore put on partial bypass by firstpositioning the venous and arterial catheters at predetermined locationsalong the vena cavae and aorta, respectively, such that the associatedflow ports may provide for the aspiration or infusion of blood,respectively, and such that balloons on the catheter outer surfaces maybe thereafter inflated to isolate the right and left heart chambers,also respectively, during full bypass. The procedure for subsequentlyweaning a patient from partial bypass to full bypass according to theknown minimally invasive cardiac bypass system example described abovegenerally proceeds as follows.

[0011] Cardioplegia agent is delivered during partial bypass in order tobegin reducing the cardiac function ultimately toward the temporarilyarrested state. The external balloons are inflated to occlude the venacavae and isolate the right heart from systemic venous circulation priorto inflating the arterial catheter's balloon to isolate the left heartfrom systemic arterial circulation. During this “weaning” period, thebypass pump circulates the blood aspirated from the vena cavae while theheart continues to pump a declining volume of residual blood from thecoronary sinus, right heart chambers, pulmonary circulation (includinglungs), and left heart chambers. As the residual volume of blood pumpingthrough the heart declines, and as the cardiac function continues towardtemporary arrest under cardioplegia effects, the balloon on the exteriorsurface of the arterial catheter is then inflated to occlude the aortaand finally achieve full or complete bypass.

[0012] Upon inflating the arterial balloon and totally occluding theaorta during the “weaning” period onto full bypass as just described,additional cardioplegia agent delivery continues distally of theinflated balloon. However, it has been observed that “back pressure” onthe cardioplegia delivery cannula during cardioplegia agent delivery,together with the pressure from the beating heart against the totallyoccluded aorta, may push the arterial balloon downstream along theaorta. As a result, a user may be required to reposition the balloon atthe initially desired location along the ascending aorta between theaortic root and the carotid arteries. It is believed that therepositioning of the arterial balloon in response to this pressureresponse may be performed while the balloon is inflated, or duringsubsequent iterations of positioning and then inflating in order toadjust for the observed post-inflation movement.

[0013] Still further to the known “minimally invasive cardiac bypasssystems,” weaning a patient off of “complete bypass” and off of thecardiopulmonary bypass pump while reestablishing physiological cardiacoutput generally requires deflation of the external balloon on theexternal surfaces of the arterial and venous catheters. However, somepatients have been observed to present complications while cardiacfunction is being reestablished, which complications may requirereturning the patient back to a full bypass condition. Therefore,patients are generally kept in surgery for a prolonged period of timesubsequent to deflating the balloons on the bypass system catheters andafter reestablishing the cardiac function in order to observe theheart's recovery. In cases where such patients are required to be putback onto cardiac bypass, the balloons must be repositioned at theirdesired location and then reinflated to isolate the heart. Particularlyregarding the occlusion balloon on the external surface of the arterialcatheter, this reinflation while the heart is pumping may present thesame repositioning issues as previously described above.

[0014] It is further believed that the arterial balloon repositioningwhich may be required during use of arterial catheters according to theknown minimally invasive cardiac bypass systems may present a cumbersomeand potentially dangerous detriment to the efficiency and safety of theoverall minimally invasive cardiac bypass procedure.

[0015] “Beating-Heart” CABG Procedures

[0016] Various methods related primarily to CABG procedures have alsobeen disclosed which are performed without placing the heart oncardiopulmonary bypass or otherwise in a pressurized blood field.

[0017] For example, even conventional open chest CABG procedures havebeen disclosed for forming a proximal anastomosis between a bypass graftand an aorta without isolating the pressurized blood field in the aortafrom the entire region along flow path in the aorta where theanastomosis is to be formed. In particular, one such method uses a“side-clamp” surgical tool which is adapted with two apposable, curvedarms that are adapted to squeeze and clamp-off only a portion of theaortic wall. This “bite” of the aortic wall is thereby isolated from theblood field by way of the side-clamp. Thus an aperture may be formed or“punched” through the aortic wall along the isolated bite and theproximal anastomosis may be completed at that aperture withoutsignificant loss of blood from the aorta. However, it is believed thatsuch externally clamping of the aorta may present some degree ofundesirable mechanical trauma to the aortic wall tissue as the aorta isin part crushed and deformed by such clamps, and furthermore that suchexternal clamping may give rise to various procedural complicationsduring some CABG procedures.

[0018] Recent advances have also been made also principally in minimallyinvasive CABG procedures which also allow a bypass graft to beanastomosed proximally to an aorta and distally to a coronary arterywithout the need to place the patient on cardiopulmonary bypass. Onesuch disclosed procedure requires particular minimally invasive deviceassemblies and methods that are adapted to form the anastomoses whilethe heart is beating. One detailed device which has been disclosed foruse in such procedures includes a “perfusion bridge” for use inperfusing a region of a coronary artery while substantially isolating adistal anastomosis site along that region from the perfused arterialblood. Another detailed device for use in such procedures provides astructure or “foot” for engaging and substantially securing the motionof the beating heart while a distal anastomosis is formed, suchaccording to at least one disclosed mode by use of suction.

[0019] At least one other known procedure involves particular devicesand methods which are adapted to temporarily arrest or otherwise reducea heart beat for relatively short periods of time, withoutcardiopulmonary bypass support, and only while various steps for forminga distal graft anastomosis are performed in a CABG procedure. Accordingto this method, the heart is temporarily “stunned” from beating, such asby stimulating the vagal nerve, while forming an anastomoses and rapidlyrecovers to resume beating quickly after the anastomosis is completed.According to this prior disclosure, it is believed that the patienttolerates such short interruptions or reductions in the heart beatsufficiently to not require cardiopulmonary bypass support. Such novelprocedures as just described which either temporarily reduce or arrestthe heart without cardiopulmonary bypass support are herein generallyreferred to as “semi-beating heart” procedures. Moreover, the terms“beating heart” in relation to the various assemblies and methodsdescribed are herein intended to generically mean any procedureoperating in a pressurized aortic blood field without the heart oncardiopulmonary bypass. Therefore, such “beating heart” assemblies andmethods are intended to encompass both the “semi-beating heart”assemblies and methods just specifically described, in addition to themore specific applications of devices and methods wherein a heart issubstantially beating in the normal physiologic rhythm for a givenpatient. Moreover, such “beating heart” procedures as just described, itis appreciated that related minimally invasive catheter bypass systemsand methods may be used to perform such procedures either in an “openchest” mode incorporating a sternotomy to directly expose the heart, aswell in “port access” mode that otherwise alleviates the need for suchsternotomies.

[0020] Further more detailed device assemblies and methods forperforming at least in part beating heart or semi-beating heart CABGprocedures, such as of the types just described, are variously disclosedin the following U.S. Patent References: U.S. Pat. No. 5,776,154 toTaylor et al.; U.S. Pat. No. 5,769,870 to Salahieh et al.; U.S. Pat. No.5,727,569 to Benetti et al.; U.S. Pat. No. 5,651,378 to Matheny et al.;U.S. Pat. No. 5,730,757 to Benetti et al.

[0021] “Direct Access” Endolumenal Aortic Isolation

[0022] Other recently developed assemblies and methods are intended toallow for direct cannulation of the aorta in order to endolumenallyclamp and isolate a region of the aorta so that various surgicalprocedures may be performed such as previously described above.According to such “direct access” procedures, an endolumenal clamp suchas an endoaortic balloon catheter is positioned within the aorta throughan introduction site through the aortic wall. According to at least oneknown specific variation, the endolumenal clamp or balloon is positionedat an endolumenal clamp site generally located between the carotidarteries and the aortic valve where it is then actuated to occlude theaorta at that site, thereby isolating the heart from the systemicarterial circulation including the carotid flow.

[0023] One more detailed example of an aorta-occluding balloon catheterwhich is intended for use in “direct access” aortic isolation isdisclosed in U.S. Pat. No. 5,428,708 to Nanu.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1A is a schematic view of one endolumenal aortic isolationcatheter which is adapted for use in an endolumenal aortic isolationprocedure.

[0025]FIG. 1B is a cross sectional view taken along line 1B-1B of FIG.1A.

[0026]FIG. 2A shows a longitudinal cross-sectional view of oneparticular endolumenal aortic isolation catheter according to theschematic view shown in FIGS. 1A-B.

[0027]FIG. 2B is a distally oriented perspective view taken through atransverse cross-section of an arterial catheter similar to that shownin FIG. 2A.

[0028]FIG. 2C is a similar transverse cross-sectional view as that shownin FIG. 2B, although showing another particular lumenal construction fora catheter such as that shown in FIG. 2A.

[0029] FIGS. 3A-B show perspective views of another particularendolumenal aortic isolation catheter, wherein FIG. 3A shows aproximally oriented perspective view of the proximal end portion of thecatheter and includes a perspective view of a transverse cross-sectiontaken through the proximal end portion of the elongate body, and whereinFIG. 3B shows a distally oriented perspective view of the distal endportion of the catheter and includes a perspective view of a transversecross-section taken through the distal end portion of the catheter'selongate body in the region of a proximal internal valve.

[0030]FIG. 3C shows a more detailed, perspective view of one particularmeans for constructing an internal valve according to the internal valvevariation shown in FIG. 3B. FIG. 4A shows a sectional perspective viewof another particular endolumenal aortic isolation catheter, andincludes a sectional perspective view of another particular internalvalve design for use in selectively occluding an internal flow lumenthrough the catheter.

[0031]FIG. 4B shows a longitudinal cross-sectional view taken along line4B-4B through the arterial catheter shown in FIG. 4A.

[0032]FIG. 4C shows a distally oriented transverse cross-sectional viewtaken along line 4C-4C through the elongate body shown in FIG. 4A.

[0033]FIG. 5A shows a longitudinal cross-sectional view of anotherendolumenal aortic isolation catheter for use in an endolumenal aorticisolation procedure.

[0034]FIG. 5B shows a distally oriented transverse cross-sectional viewtaken through the elongate body of an arterial catheter similar to thatshown in FIG. 5A.

[0035]FIG. 6 shows a longitudinal cross-sectional view of anotherendolumenal aortic isolation catheter for use in performing anendolumenal aortic isolation procedure.

[0036]FIG. 7A shows a perspective view of the distal end portion ofanother endolumenal aortic isolation catheter for use in performing anendolumenal aortic isolation procedure.

[0037]FIG. 7B shows a perspective view of the same distal end portion ofthe endolumenal aortic isolation catheter shown in FIG. 7A, althoughshowing the external shunt valve in a radially expanded condition whichcharacterizes a shunting position.

[0038]FIG. 7C shows a sectional longitudinal cross-section taken alongline 7C-7C through the funnel formed by the external shunt valve shownin FIG. 7B.

[0039] FIGS. 8A-B show perspective views of another endolumenal aorticisolation catheter, wherein an external shunt valve is shown in radiallycollapsed and radially expanded conditions, respectively, whichcharacterized the open and closed positions, respectively, for thevalve.

[0040]FIG. 8C shows a longitudinal cross-section taken along line 8C-8Cthrough the endolumenal aortic isolation catheter shown in FIG. 8B, andshows internal valves adjusted to a predetermined combination of theirrespective open and closed positions.

[0041]FIG. 8D shows a similar longitudinal cross-section as FIG. 8C andtaken along line 8D-8D of the catheter shown in FIG. 8B, althoughshowing the internal valves adjusted to a different predeterminedcombination of their respective open and closed positions.

[0042]FIG. 9 shows a perspective view of a endolumenal venous isolationcatheter assembly during use in isolating a right ventricle from thevena cavae and while aspirating venous blood from the vena cavae.

[0043]FIG. 10A shows a perspective view of another endolumenal venousisolation catheter for use in isolating a right ventricle from the venacavae, and shows a longitudinally cross sectioned side view through thecatheter in the region of an external valve.

[0044]FIG. 10B shows a similar view of the venous catheter shown in FIG.10A, although showing the valve member of the external valve after beingactuated from a first radial position to a radially displaced positionwhich is adjacent to the elongate body.

[0045]FIG. 10C shows a longitudinally cross-sectioned side view of theexternal valve shown in FIGS. 10A-B, although further showing twoexpandable members of the valve member which are separated by a space.

[0046]FIG. 10D shows a similar longitudinally cross-sectioned side viewof the external valve shown in FIG. 10C, although showing each of thetwo expandable members further adjusted to a radially expandedcondition.

[0047]FIG. 11 shows a medical device system during one mode of use inisolating a heart from the venous and arterial systemic systems in apatient.

[0048]FIG. 12 shows a similar view of the medical device system shown inFIG. 11, although showing an external shunt valve during anothersequential mode of use in performing a minimally invasive bypassprocedure.

[0049]FIG. 13 shows a similar view of the medical device system shown inFIGS. 11-12, although showing the external valve during anothersequential mode of use.

[0050]FIG. 14A shows a perspective view of the distal end portion ofanother endolumenal aortic isolation catheter adapted for use in a“beating heart” aortic isolation procedure.

[0051]FIG. 14B shows a perspective view of the endolumenal aorticisolation catheter shown in FIG. 14A, except showing the catheter duringa mode of use for isolating a proximal anastomosis site along an aorta,and schematically showing an expansion actuator assembly as a part of anoverall medical device system.

[0052]FIG. 15A shows a perspective view of the distal end portion ofanother endolumenal aortic isolation catheter adapted for use in a“beating heart” endolumenal aortic isolation procedure.

[0053]FIG. 15B shows a perspective view of the endolumenal aorticisolation catheter shown in FIG. 15A, except showing the catheter duringone mode of use when isolating a proximal anastomosis site along anaorta.

[0054]FIG. 16 shows a cross-sectioned side view of the distal endportion of an endolumenal aortic isolation catheter which is similar tothat shown in FIGS. 15A-B, and shows the catheter to include onespecific type of isolation assembly.

[0055]FIG. 17 shows a side cross-section view of the distal end portionof another arterial catheter also similar to that shown in FIGS. 15A-B,and shows the arterial catheter to include another specific type ofaorta isolation assembly.

[0056]FIG. 18 shows a longitudinal perspective view of an endolumenalaortic isolation catheter with two balloons such as that shown in FIGS.14A-B, although showing the catheter during one mode of use in a directaccess endolumenal aortic isolation procedure.

[0057]FIG. 19A shows a longitudinally cross-sectioned side view of thedistal end portion of a direct access endolumenal aortic isolationcatheter during one mode of use which allows the heart to pump bloodinto the systemic arterial circulation through a distal internal flowlumen provided along the catheter.

[0058]FIG. 19B shows a similar view of the direct access endolumenalaortic isolation catheter shown in FIG. 19A, although shows the catheterduring another mode of use which isolates the heart from a patient'ssystemic arterial circulation which is being perfused by an artificialcardiopulmonary bypass pump which is coupled to a proximal internal flowlumen along the catheter.

[0059]FIG. 19C schematically shows a partially exploded side view of thedistal end portion of an internal valve assembly which is adapted foruse in the direct access endolumenal aortic isolation catheter shown inFIGS. 19A-B.

[0060]FIG. 19D shows a longitudinally cross-sectioned side view of oneparticular internal valve assembly such as that shown schematically inFIG. 19C.

[0061]FIG. 20 shows a longitudinally cross-sectioned side view of thedistal end portion of another direct access endolumenal aortic isolationcatheter of the invention during a similar mode of use as shown in FIG.19A, and shows in shadow a second position for an internal flow valveassembly during another mode of use as described above by reference toFIG. 19B.

[0062]FIG. 21 illustrates a direct access endolumenal aortic isolationcatheter having a movable internal valve.

[0063]FIG. 22 shows a perspective view of the distal end portion ofanother endolumenal aortic isolation catheter adapted for use in a“beating heart” aortic isolation procedure.

[0064]FIG. 22B shows a perspective view of the endolumenal aorticisolation catheter shown in FIG. 15A, except showing the catheter duringone mode of use when isolating a proximal anastomosis site along anaorta.

[0065]FIG. 23A shows a perspective view of the distal end portion ofanother endolumenal aortic isolation catheter adapted for use in a“beating heart” endolumenal aortic isolation procedure.

[0066]FIG. 23B shows a perspective view of the endolumenal aorticisolation catheter shown in FIG. 15A, except showing the catheter duringone mode of use when isolating a proximal anastomosis site along anaorta.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0067] FIGS. 1A-8D show varied detail of particular arterial cathetervariations which are adapted for use in a minimally invasive cardiacbypass system. FIGS. 9A-10D show varied detail of particular venouscatheter variations which are also adapted for use in a minimallyinvasive cardiac bypass system. FIGS. 11-13 show a minimally invasivebypass catheter system during sequential modes of use in a cardiacbypass procedure. FIGS. 14-17 show the distal end portion of aparticular endolumenal aortic isolation catheter having an endolumenalclamp assembly that is a shaped balloon which is adapted to allow aproximal anastomosis to be formed along the aorta while the heart isbeating and without substantial loss of blood. FIGS. 18-22B show variousmodes of a direct access endolumenal aortic isolation system accordingto the invention.

[0068] Cardiac Bypass Arterial Catheter

[0069] According to a cardiac bypass aspect of the invention, anarterial catheter is provided which is adapted such that its distal endportion may be positioned within the aortic root adjacent to the leftventricle while its proximal end portion is coupled outside of the bodyto a cardiopulmonary bypass pump. An external shunt valve anchors to theaortic wall along the ascending aorta between the aortic root and theaortic arch and allows for antegrade aortic blood flow to shunt from theaortic root, through an internal flow lumen within the catheter, and outan intermediate flow port located along the catheter proximally of theexternal shunt valve, usually in the region of the aortic arch. Eitherduring the cardiac output decline due to cardioplegic effects, or oncethe heart is substantially arrested from beating and is substantiallydrained of blood, a distal internal valve closes the internal flow lumenbetween the distal port adjacent the aortic root and the intermediateflow port in the region of the aortic arch, thereby isolating the leftheart chambers from systemic arterial circulation. With the distalinternal valve closed, oxygenated blood may then be perfused from theproximally coupled bypass pump, distally through the internal flowlumen, and out the intermediate flow port into the systemic circulation.

[0070]FIG. 1A shows a schematic representation of one arterial catheterfor endolumenal aortic isolation such as according to the cardiac bypassprocedure just described. Arterial catheter (1) is shown to include anelongate body (2) which includes an external shunt valve (3) on theouter surface of the elongate body's distal end portion. Elongate body(2) further includes an internal flow lumen (not shown in FIG. 1A) whichcommunicates externally of the elongate body through a distal flow port(4), which is located distally of external shunt valve (3), and alsothrough an intermediate flow port (5), which is located along the distalend portion of the elongate body proximally of external shunt valve (3).Each of the particular distal and intermediate flow ports (4, 5) shownin FIG. 1A includes a plurality of apertures which are adapted to allowfor sufficient wall rigidity for the catheter to function in apercutaneous transluminal procedure and also to allow for sufficientblood flow to communicate with the internal flow lumen through thoseports.

[0071]FIG. 1A further shows a distal internal valve (6), which islocated within the internal flow lumen distally of intermediate flowport (5), and also a proximal internal valve (7), which is locatedwithin the internal flow lumen proximally of intermediate flow port (5).Each of the distal and proximal internal valves (6, 7) is adjustablefrom an open position, which allows for fluid flow to pass through theinternal flow lumen, to a closed position, which is adapted tosubstantially occlude the internal flow lumen and prevent fluid flowfrom passing therethrough. Both distal and proximal internal valves (6,7) are shown in their respectively closed positions in FIG. 1A for thepurpose of illustrating their location in relation to intermediate flowport (5). A predetermined combination of the open and closed positionsfor the respective distal and proximal internal valves (6, 7) shown inFIG. 1A may be selected such that a predetermined flow pattern isprovided from the internal flow lumen and through these ports. Forexample, the distal internal valve (6) may be adjusted to the openposition while the proximal internal valve (7) is adjusted to the closedposition. In that arrangement, expansion of the external shunt valve (3)within an aortic arch in the region of the aortic root isolates anexterior space between the catheter and the aortic wall from antegradeaortic blood flow while that flow is shunted into distal flow port (4),through the internal flow lumen, out intermediate flow port (5), andinto a proximal region of the aorta located proximally of the externalshunt valve (3). Alternatively, distal internal valve (6) may beadjusted to the closed position while proximal internal valve (7) isadjusted to the open position. In this arrangement, intermediate flowport (5) may be fluidly coupled to a cardiopulmonary bypass pump via aproximal flow port (not shown) through which the internal flow lumencommunicates exteriorly of the elongate body (2) along its proximal endportion (not shown).

[0072] Further shown in FIG. 1A are cardioplegia delivery port (8) andventricular venting port (9), which are each shown to include aplurality of apertures. These ports (8, 9) are shown located on asingle, common cannula member which extends from the elongate body (2)distally of the distal flow port (4) and external shunt valve (3). It isfurther contemplated however that these delivery ports may also be onseparate cannula members, and in either case the common or separatecannula member may be fixed relative to the elongate body (2) or may beindividually slideable relative to elongate body (2), such as by beingcoaxially disposed within a lumen extending through the elongate body.

[0073] Regardless of the particular cannula design, however, thecardioplegia delivery port (8) is adapted to be positioned within theaortic root such that cardioplegia agent may be delivered to the heartvia the coronary arteries stemming therefrom. As such, cardioplegiadelivery port (8) may also be positioned adjacent to the distal flowport (4), so long as cardioplegia delivery port (8) is located distallyof external shunt valve (3) in order to locally delivery thecardioplegia agent to the left heart and isolate the cardioplegia agentdelivered from systemic circulation. The ventricular venting port (9) isadapted to be positioned within the left ventricle, ideally within theapex of that chamber, when the external shunt valve (3) is positionedand anchored within the aortic arch. In this manner the ventricularventing port (9) is adapted to aspirate blood from the left ventricle tocreate a substantially bloodless field during cardiac surgery when theheart is on bypass.

[0074]FIG. 1B schematically shows the luminal structure of the apparatusof FIG. 1A. Interior flow lumen (2′) extends throughout the catheterslength between the distal flow port (4) shown in FIG. 1A and a proximalflow port located on the proximal end portion of the elongate body (notshown), and further communicates exteriorly of the elongate body (2)through intermediate flow port (5) shown in FIG. 1A. It is furthercontemplated that more than one lumen may function as internal flowlumens according to the present invention, so long as the distal andintermediate flow ports may be selectively fluidly coupled and theintermediate and proximal flow ports may also be selectively fluidlycoupled. In one variation not shown, a distal internal flow lumen mayextend between distal and intermediate flow ports, respectively, while aproximal internal flow lumen extends between proximal and intermediateflow ports, also respectively. According to this variation, separateintermediate flow ports may be provided in communication with the distaland proximal internal flow lumens, respectively, with the distal andproximal internal valves also positioned within the distal and proximalinternal flow lumens, also respectively.

[0075]FIG. 1B further shows a schematic representation for externalshunt valve actuating lumen (3′), distal internal valve actuating lumen(6′), proximal internal valve actuating lumen (7′), cadioplegia deliverylumen (8′), and left ventricular venting lumen (9′). These lumens arerespectively coupled to external shunt valve (3), distal and proximalinternal valves (6, 7), and cardioplegia and left ventricular ventingports (shown in FIG. 1A). Furthermore, these lumens extend along theproximal end portion of the elongate body (not shown) and arerespectively adapted to couple to an external shunt valve actuator, adistal internal valve actuator, a proximal internal valve actuator, apressurizeable cardioplegia agent source, and a decompression pump.Moreover, the present invention should not be limited to the specificluminal structures and proximal actuation means described herein indetail and modifications and improvements thereof may be suitableaccording to one of ordinary skill.

[0076]FIG. 2A shows an arterial catheter variation which includes oneparticular internal valve variation that uses an expandable member toselectively occlude flow through an internal flow lumen within thecatheter. Arterial catheter (10) is shown in FIG. 2A to include anelongate body (11) which includes an inner tube (12) that forms theinternal flow lumen (12′). Distal internal valve (16) and proximalinternal valve (17) are expandable members, specifically shown in FIG.2A as expandable balloons, which are positioned distally and proximallyadjacent to intermediate flow port (15), respectively, within internalflow lumen (12′). Intermediate flow port (15) further includes aplurality of apertures through inner tube (12) and through which theinternal flow lumen (12′) communicates exteriorly of elongate body (11).Each of distal and proximal internal valves (16, 17) is adjustable froma radially collapsed position, which characterizes an open position thatallows for fluid to flow through the internal flow lumen, to a radiallyexpanded condition which characterizes the closed position, which isadapted to substantially occlude fluid flow through the internal flowlumen. For the purpose of further illustration, proximal internal valve(17) is shown in the radially collapsed condition, which is the openposition, and distal internal valve (16) is shown in the radiallyexpanded condition, which is the closed position.

[0077]FIG. 2A further shows a shadowed view of an additional flow portwhich is a second intermediate flow port (15′) positioned proximally ofproximal internal valve (17). Where multiple intermediate flow ports areprovided according to this variation, a proximal internal valve ispositioned proximally of the most proximally positioned intermediateflow port, and an intermediate internal valve is positioned along theinternal flow lumen between each adjacent pair of intermediate flowports. Thus, when second intermediate flow port (15′) is included in thecatheter shown in FIG. 2A, proximal internal valve (17) would actuallybe an “intermediate internal valve” and another proximal internal valve(not shown) would be provided along the internal flow lumen proximallyadjacent to the second intermediate flow port (15′).

[0078] Further to the multiple intermediate flow port variation justdescribed, the distal, intermediate, and proximal internal valves may beadjusted to a predetermined combination of their respectively open andclosed positions in order to provide fluid communication between eitherthe proximal flow port or the distal flow port and a desired combinationof the intermediate flow ports along the elongate body's length. Forexample, in the case where two intermediate flow ports (15, 15′) areprovided such as according to FIG. 2A, antegrade aortic blood flow maybe shunted proximally through internal flow lumen (12′) from the distalflow port (not shown in FIG. 2A) and through only intermediate flow port(15) by adjusting internal valves (16, 17) to their open and closedpositions, respectively. Alternatively, by opening both internal valves(16, 17) and closing a proximal internal valve (not shown) locatedproximally of second intermediate flow port (15′), the antegrade aorticblood flow may be shunted from the aortic root and to proximal regionsof the aorta adjacent to both intermediate flow ports (15, 15′). Adifferent combination of internal valves may be adjusted to theirrespective open and closed positions in order to allow for thepreselected distal perfusion of oxygenated blood from a bypass pumpcoupled to a proximal flow port (not shown) and through onlyintermediate flow ports (15′) or both intermediate flow ports (15′, 15).

[0079] The controllable perfusion of oxygenated blood along the arterialcatheter's length as just described is believed to address a dichotomyof functional requirements normally placed upon a minimally invasivebypass arterial catheter. In one aspect, the arterial catheter must behave a large enough internal flow lumen to carry oxygenated blood fromthe bypass pump or from the aortic root and into the aortic arch at flowlevels which mimic physiological circulation. In another aspect,however, the arterial catheter itself provides occlusive resistance toantegrade arterial flow around the catheter between the intermediateflow ports located within the aortic arch and the catheter's entrancesite, usually at the femoral artery. With the ability to perfuse bloodflow through a predetermined length of ports along the arterialcatheter, much of the desired downstream blood flow may be perfused outfrom the catheter further down the arterial tree and thus minimize theotherwise occlusive nature of the catheter shaft.

[0080] However, the controllable perfusion along the catheter's lengthaccording to the multiple valve and port embodiment shown in FIG. 2A haslimited controllability. For example, a distal flow port may communicatewith a controllable length of ports going distal to proximal along thecatheter, but may not communicate with a selected port or ports on aproximal end portion of the catheter at the exclusion of more distal orintermediate ports. A similar limitation is present for the proximalflow port which is adapted to couple to an outlet port of acardiopulmonary bypass pump. By selecting a specific internal valve toclose, the proximal flow port communicates with any number ofintermediate flow ports along the catheter proximally of the closedvalve, but is isolated from intermediate flow ports located distally ofthe internal flow lumen. However, it may be desirable to select only oneor a few distally disposed intermediate ports for active perfusion fromthe pump, such as for example an intermediate flow port locatedproximally adjacent to the external shunt valve which is adapted to bepositioned adjacent to the ostia of the carotid arteries from the aorticarch.

[0081] Therefore, it is further contemplated that a slideable externalsheath may be positioned externally of the catheter shaft and which isadjustable to coaxially block and occlude selected intermediate flowports along the catheter length. When a patient is on full or partialbypass, the slideable sheath may be positioned to a desired locationdistally along the catheter shaft such that a predetermined length ofdistally disposed intermediate flow ports is in communication with theproximal flow port, which predetermined length includes an intermediateport proximally adjacent to the external shunt valve but excludes anyintermediate ports located more proximally along the catheter shaft.

[0082] Further to the internal valve variation of FIG. 2A, distal andproximal internal valves (16, 17) are expandable balloons which areshown to be fluidly coupled to distal and proximal valve actuatinglumens (18, 19), respectively, through ports formed through the wall ofinner tube (12), shown for example in FIG. 2A at internal valve port(14). Various means for coupling the internal valves to their respectiveactuating members or lumens may be suitable according to one or ordinaryskill. One particular means for providing such coupling is shown in FIG.3C (described in detail below), which is particularly adapted for use inthe elongate body variation shown in FIGS. 3A-B, but which may besuitably modified for use in the variation shown and described here byreference to FIG. 2A.

[0083] In order to actuate expansion of the balloons which form theinternal valves of the FIG. 2A variation, distal and proximal valveactuating lumens (18, 19) are also fluidly coupled to an internal valveactuator at the proximal end portion of the elongate body (not shown).The internal valve actuator may include one common actuator whichincludes a switch to selectively adjust each valve to its respectiveopen or closed position, or may include separate, individual proximaland distal valve actuators, each coupled to one of the internal valvesto adjust it between the respective valving positions. In either thecommon actuator or individual actuator case, the internal valve actuatorgenerally includes a pressurizeable source of fluid for the ballooninternal valve variation shown in FIG. 2A.

[0084] The expandable balloons used for internal valves (16, 17) shownin FIG. 2A may be constructed as follows. In one variation, the balloonis constructed from a relatively compliant material which stretches whenpressurized, such as for example a latex rubber, polyurethane, orsilicone material. In this compliant balloon variation, the balloon mayform a simple tubular member or otherwise a relatively small bladderwhen in the radially collapsed condition which characterizes the openposition for the valve. Preferable to the small bladder variation andwhen placed within the internal flow lumen, the balloon is generallymaintained under negative vacuum pressure when in the open position soas to minimize the occlusive nature of the balloon within the flowlumen. Upon pressurizing the relatively compliant balloon, the balloonmaterial stretches and expands to form a balloon-like shape in theradially expanded condition which characterizes the closed position andblocks the internal flow lumen.

[0085] In another internal valve variation, the balloon is constructedfrom a relatively non-compliant material which is preformed into itsdesired shape in the radially expanded condition and is thensubsequently folded into the radially collapsed condition whichcharacterizes the open position for the valve. Such a relativelynon-compliant balloon may be comprised of for example a radiatedpolyethylene material such as linear low or high density polyethylene,polyester terepthalate (PET), polyimide, Nylon, or polyolefin copolymer.Upon pressurization the folded, relatively non-compliant balloon isfilled and unfolds to its radially expanded condition whichcharacterizes the closed position and blocks the internal flow lumen.

[0086] While the particular internal valve variation shown in FIG. 2Aplaces expandable balloons within the internal flow lumen (12′), otherinternal valve variations may also be suitable so long as the valve isadjustable from an open position, which allows fluid to flow through theinternal flow lumen, to a closed position, which substantially occludesthe internal flow lumen and blocks flow therethrough. For example,expandable members such as the balloons shown in FIG. 2A may bepositioned adjacent to an inner tube which forms the internal flowlumen, rather than within the flow lumen. According to this variation,expansion of the expandable valve member to the radially expandedcondition collapses the adjacent inner tube to create the closedposition. By adjusting the expandable valve member to the radiallycollapsed condition, the inner tube distends to the open position forflow. This variation beneficially removes the expandable member of theinternal valve from the flow lumen, which is believed to provideimproved hemodynamics through a smoother surface within that lumen.

[0087] Further to the “adjacent” expandable valve member variation, theinner tube may be in one aspect a relatively thin-walled, flaccid membersuch as a thin polyethylene or a TeflonTM tubing such as those used informing artificial graft members. The thin, flaccid inner tubing whichforms the internal flow lumen according to this particular variation maybe provided as follows. The thin, flaccid inner tubing which forms theinternal flow lumen is a first inner tubing which has a diameter thatapproximates the inner diameter of a second inner tubing. The expandableballoon resides between the first and second inner tubings which arecoaxial. With the internal valve in the radially collapsed conditionwhich characterizes the open position, the first inner tubing distendsfrom pressure within the internal flow lumen and fills the innerconfines of the second, coaxial inner tubing. This pressure is providedfor example by blood flowing either from the aorta and between thedistal and intermediate flow ports or from the cardiopulmonary bypasspump and between the proximal and intermediate flow ports. However, whenthe internal valve is adjusted to the radially expanded condition whichcharacterizes the closed position, the region of the first inner tubingadjacent to the internal valve is collapsed and the flow lumen isclosed.

[0088] In a further variation (not shown) of the “adjacent” expandablevalve member, the inner tube is a resilient tubular member, such as forexample a polyurethane or silicone tubing. According to this variation,the resilient tubing elastically returns to the tubular state uponadjusting the valve to the open position after collapsing the tubingwith the valve in the closed position.

[0089] In still another expandable internal valve member embodiment (notshown), a mechanically expandable member may be employed to selectivelyopen and close the lumen, as opposed to the hydraulic actuationmechanism of the previously described balloon variations. In one suchmechanical valve variation, an expandable cage constructed of coiled orbraided metal ribbon or wires may be substituted for the inflatableballoons. In a more detailed embodiment where the cage is positionedwithin the flow lumen, such a cage would preferably include adistensible polymeric skin in a composite construction in order tosubstantially occlude flow therethrough during the expanded, closedposition. In an alternative embodiment which places the expandable cagemember adjacent to the internal flow lumen, however, such a compositeskin might not be required.

[0090] In another further mechanical valve variation (also not shown), astop-cock may be placed along the internal flow lumen. The open positionfor the stopcock variation is characterized a stopcock lumen beingregistered and aligned with the internal flow lumen. The stopcock'sclosed position is characterized by the stopcock lumen being out ofalignment from the internal flow lumen such that a wall of the stopcockblocks flow through the flow lumen. Adjustment of the stopcock betweenthe open and closed positions may be accomplished mechanically, such asfor example by keying a longitudinally adjustable actuating member to acurved surface of the stopcock in a ratchet-and-pawl mechanism to rotatethe stopcock.

[0091] Still a further mechanical internal valve variation (also notshown) includes a cam assembly with a cam surface that biases alongitudinally adjustable member radially into the internal flow lumenor against an inner tubing to collapse the flow lumen when thelongitudinally adjustable member is advanced against the cam surface.

[0092] In addition to the several internal valve variations justpreviously described, other further variations not herein specificallydescribed may also be suitable for use according to the describedembodiments, as would be apparent to one of ordinary skill from thisdisclosure. Further to the shaft construction shown in the arterialcatheter embodiment of FIG. 2A, outer tubing (13) is shown surroundinginner tubing (12) as well as the internal valve actuating lumens (18,19) to form elongate body (11). Alternative variations of acceptableluminal structures for use in forming the elongate body of the FIG. 2Aarterial catheter variation are provided in detail in FIGS. 2B-C, eachshowing a proximal end view through a cross section taken through acatheter's elongate body similar to that shown in FIG. 2A, and eachshowing an end perspective view of internal valves (16, 17) in theirclosed and open positions, respectively, within the internal flow lumen.

[0093] One specific catheter shaft construction wherein each individuallumen is formed by a separate, individual tubing is shown in FIG. 2B.According to the FIG. 2B shaft variation, a bundle of inner tubings iscoaxially surrounded and bound by an outer tubing (13) to form one,overall composite structure. Included within the bundle formed by outertubing (13) are inner tubing (12), internal valve actuating lumens (18,19), external shunt valve actuating lumen (20), and cardioplegiadelivery and ventricular venting lumens (21, 22).

[0094] Unlike the other lumens shown in FIG. 2B, cardioplegia deliveryand ventricular venting lumens (21, 22) are shown in FIG. 2B to beformed by a dual lumen extrusion. This particular design is believed tobe particularly useful in the bundled composite shaft variation becausethese particular lumens are preferably extended distally beyond thestructures along the elongate body's distal end portion to which theother lumens couple and terminate. For example, the internal valveactuating lumens (18, 19) terminate distally in the internal valves,such as at valves (16, 17) shown in FIG. 2A or at valves (6, 7) shown inFIG. 1A. Furthermore, external shunt valve actuating lumen (20)terminates distally where it is fluidly coupled to the external shuntvalve, such as is shown at external shunt valve (3) in FIG. 1A. Stillfurther, the internal flow lumen formed by inner tubing (12) terminatesdistally at a distal flow port such as distal flow port (4) shown in FIG1A.

[0095] Another acceptable luminal variation for use in forming theelongate body of an arterial catheter according to the variation shownin FIG. 2A is shown in FIG. 2C. In this variation, a single, four lumenextrusion (32) forms internal flow lumen (32′), an external shunt valveactuating lumen (36), and cardioplegia delivery and ventricular ventinglumens (37, 38). Separate, individual internal valve actuating lumens(34, 35) are also shown bundled together with four lumen extrusion (32)within an outer tubing (33) to form the composite shaft of thisvariation.

[0096] The positioning of the separate lumens in the four lumenextrusion (32) of FIG. 2C enhances the ability for those separate lumensto be cut away from the rest of the extrusion where an adaption is to bedesirably formed. For example, the portion of four lumen extrusion (32)which forms external shunt valve actuating lumen (36) may be removeddistally to where external shunt valve actuating lumen (36) is to befluidly coupled and adapted to the external shunt valve (not shown),thereby extending a three lumen extrusion containing internal flow lumen(32′), cardioplegia delivery lumen (37), and ventricular venting lumen(38) distally from that adaption. Similarly, the three lumen extensionof four lumen extrusion (32) may be further modified distally of theexternal shunt valve adaption, such that a two lumen extension whichforms cardioplegia delivery and ventricular venting lumens (37, 38) maybe carried distally of the cut-away portion forming the internal flowlumen (32′). However, in a further variation to the latter example (notshown), the three lumen extension of the four lumen extrusion (32) mayalternatively terminate at one location, wherein cardioplegia deliveryand ventricular venting lumens (37, 38) may be adapted to a separatedual lumen cannula (or two separate tubings) which carry the lumensfurther distally where they terminate in their respective distal ports(not shown). One suitable assembly method and material construction forthe individual tubings used in the bundled composite shaft variationsjust shown and described by reference to FIGS. 2B-C may be provided asfollows. The outer tubing, such as outer tubing (13) in FIG. 2B or outertubing (33) in FIG. 2C, is preferably a heat shrinkable polymer whichmay be comprised of for example irradiated polyethylene,polytetrafluoroethylene (PTFE), fluoro ethyl propylene (FEP), polyesterterepthalate (PET), or polyimide. In general, such a heat shrinkablepolymer is heated and then expanded from a memory state to an expandedstate. In the expanded state, the heat shrink tubing is loaded coaxiallyover the other inner tubings. During subsequent reheating, the outer,expanded, heat shrink tubing recovers toward the smaller diameter memorystate and thus shrinks around the inner tubings to form the composite.

[0097] The inner tubings according to the bundled construction justdescribed are preferably adapted to resist deformation and also toretain their luminal integrity under the elevated temperatures of theheat shrink process just described. To that end, placement of mandrelsthrough the bundled tubings is one method which is believed to assist inmaintaining these interior lumens during the heat shrink process. In thealternative or in addition to providing mandrels within the respectivelumens, one or all of the inner tubings may also be made of anirradiated polymer, which may be similar to that used for the outer heatshrink tubing, although such inner radiated tubings are preferably attheir memory state and are collapsed such that they maintain theirlumens during the heat shrink step. In a further variation, the innertubings may be made of a material with a melt temperature or glasstransition temperature which is higher than the temperature required toshrink the outer tubing. In still a further variation, one or all of theinner tubings may include a reinforcing member such as a metallic coilor braid imbedded within or laminated with a polymeric tube whichassists in maintaining the tubular shape when the polymer mightotherwise flow and reconfigure when the bundle is heated with the outertubing. Further to the heat shrink-bundling variations just described,one or more additional polymeric members may also be provided between oraround the individual inner tubings as they are bundled and heated toform the composite. Such additional polymeric members preferably arecomprised of a material which melts and flows at the temperatures usedto shrink the outer heat shrink tubing. For example, non-irradiated lowdensity polyethylene tubings or beading mandrels may be included aroundor between the inner tubings, respectively. When the bundle is heatedduring the heat shrink-bundling process, this additional polymerictubing or mandrel melts and flows between the inner and outer tubingsand provides a binding agent therebetween. Further to this variation, aflexible epoxy or other adhesive material may also be provided betweenthe interior tubings as a binding agent during the heat shrink process.

[0098] Another particular arterial catheter for use in a cardiopulmonarybypass procedure is shown in two cut-away perspective views in FIGS.3A-B. FIG. 3A shows proximal end portion (42) of elongate body (41) ofarterial catheter (40) in a proximally oriented perspective view whichincludes a transverse cross section taken through the tubing (43) whichforms the elongate body (41). FIG. 3B shows the distal end portion (62)of the same elongate body (41) in a distally oriented perspective viewwhich includes a transverse cross section through a region of the distalend portion (62) which includes proximal internal valve (67). Theparticular variation shown in FIGS. 3A-B for tubing (43) which formselongate body (41) includes a single, six lumen extrusion that includesall the lumens of the catheter shaft.

[0099] Tubing (43) forms internal flow lumen (43′) which includes aproximal flow port that is schematically shown in FIG. 3A as it isproximally coupled to cardiopulmonary bypass pump (50). Internal flowlumen (43′) is further shown in FIG. 3B along the distal end portion(62) of the catheter where it communicates externally of the elongatebody through distal flow port (68) and intermediate flow port (66). Eachof distal flow port (68) and intermediate flow port (66) are shown inFIG. 3B to include a plurality of apertures, wherein those formingdistal flow port (68) include apertures along the circumference of adistal extension of tubing (43) beyond external shunt valve (70) andalso an end port which terminates the lumen along the longitudinal axis.For the purpose of clarity, however, general reference to “distal flowport” in regards to the internal flow lumen is intended to herein referto the end port and may optionally include the circumferential aperturesshown in FIG. 3B. Further to the end port forming at least in partdistal flow port (68), that port may also provide a means for coaxiallyengaging and tracking over a guidewire, as will be described in somemore detail below by reference to FIGS. 11-13. Distal and proximalinternal valve actuating lumens (44, 45) are shown in FIG. 3Aschematically coupled to an internal valve actuator (51) along proximalend portion (42) of elongate body (41). Internal valve actuator (51) mayinclude a common actuator or two separate individual actuators as waspreviously described for the FIG. 2A variation. Distal internal valveactuating lumen (44) is further shown in FIG. 3B as it is coupled to thedistal internal valve (64), shown in shadow within internal flow lumen(43′) via valve coupling means (44′) in the distal end portion (62) ofelongate body (41). Proximal internal valve actuating lumen (45) isdistally coupled to proximal internal valve (65) along the distal endportion of the elongate body via valve coupling means (45′), which isshown in cross-section through proximal internal valve (65) in FIG. 3B.

[0100] External shunt valve actuating lumen (46) is also shown in FIG.3A as it is proximally coupled to an external shunt valve actuator (56),and is further shown in FIG. 3B as it terminates distally in inflationport (46′) where it is in fluid communication with external shunt valve(70). External shunt valve actuator (56) is thus adapted to actuateexpansion of external shunt valve (70) from a radially collapsedposition to a radially expanded position via external shunt valveactuating lumen (46). In the expandable balloon variation shown forexternal shunt valve (70) in FIG. 3B, external valve actuator (56) shownin FIG. 3A is a pressurizeable fluid source which is adapted to inflatethe expandable balloon by filling the balloon with fluid throughexternal shunt valve actuating lumen (46) and inflation port (46′).

[0101] Further to the expandable balloon which forms external shuntvalve (70) shown in FIG. 3B, the balloon is shown to have a shape whenin the radially expanded condition which forms an anchor (71) and afunnel (72). More specifically, anchor (71) is formed by a region ofexternal shunt valve (70) which has an outer diameter when expanded thatis adapted to engage an interior wall of an aorta in the region of theascending aorta. Funnel (72) is shown in shadow to have a tapered innersurface with a proximally reducing inner diameter from a relativelylarge inner diameter portion, which approximates the inner diameter ofthe aortic root where the external shunt valve (70) is to be positioned,to a relatively small inner diameter portion, which is adjacent to andapproximates the outer diameter of distal flow port (68), which may alsohave a plurality of apertures as shown in FIG. 3B.

[0102] Cardioplegia delivery lumen (47) and ventricular venting lumen(48) are also proximally coupled to a pressurizeable cardioplegia agentsource (57) and to a decompression pump (58), respectively, as is alsoshown schematically along the proximal end portion (42) of elongate body(41) in FIG. 3A. These lumens are further shown in FIG. 3B as theyextend distally of the distal flow port (68) where they terminate in acommon cannula member in cardioplegia delivery and ventricular ventingports (not shown), also respectively.

[0103]FIG. 3C shows a more detailed, perspective view of one particularmeans for coupling an internal valve actuating lumen to an internalvalve located within the internal flow lumen according to the variousembodiments described, and is shown particularly adapted for use asproximal and distal valve coupling means (44′, 45′) shown in FIG. 3B forthe purpose of illustration.

[0104] In more detail, FIG. 3C shows elongate body (90) to include aninternal valve actuating lumen (91) which has been cut-away along itsdistal portion such that the lumen terminates in a valve coupling port(93). An internal valve port (94) is also shown along the cut-awayportion of elongate body (90) and communicates with the internal flowlumen (not shown). Internal valve (85) is adapted to the internal flowlumen and also to the internal valve actuating lumen (91) via adaptionmember (81).

[0105] Further detail shown in FIG. 3C for internal valve (85) includesa valve bladder (86), a valve neck (88), a lip (87), and a valveinflation port (89) which communicates with the internal cavity formedby valve bladder (86). This internal valve variation shown is of therelatively compliant type such as that described previously withreference to FIG. 2A, and preferably the individual valve componentsjust described are formed of a uniform material, such as one moldedconstruction.

[0106] Valve bladder (86) may be positioned within the internal flowlumen of the catheter as follows. First, a stiffening mandrel (notshown) is inserted into valve bladder (86) through valve inflation port(89) until valve bladder is stretched and distended with a sufficientlynarrow width to fit within the internal valve port (94). The stiffeningmandrel is then used to insert the stretched valve bladder (86) throughthe internal valve port (94) until lip (87) acts as a stop around theouter surface of internal valve port (94). Valve neck (88) is therebycoaxially seated within internal valve port (94) and preferably has anouter diameter which is adapted with a tight tolerance to the innerdiameter of internal valve port (94), although an adhesive may also beapplied to the interface in order to provide a fluid tight seal. Uponremoving the stiffening mandrel, valve bladder (86) reconforms to itsresting shape in the radially collapsed condition which characterizesthe open position within the internal flow lumen, which shape is shownin FIG. 3C and is preferably adapted to optimize hemodynamics for bloodflow therearound. Adaption member (81) includes an adaption lumen (82)extending between a proximal adaption port (83) and a distal adaptionport (84). Proximal adaption port (83) is adapted to couple to valvecoupling port (93), as is shown by a schematic arrow in FIG. 3C. Thisadaption may be formed by potting the proximal end portion of adaptionmember (81) which includes proximal adaption port (83) in adhesivewithin internal valve actuating lumen (91). Alternatively, adaptionmember (81) may be comprised of an irradiated polymer, preferably anirradiated polyethylene, or still more preferably irradiated highdensity polyethylene, which is necked to a reduced outer diameter, thenadvanced within the internal valve actuating lumen (91) through port(93), and subsequently reheated and expanded to engage the interiorsurface of that lumen (and perhaps melt to that surface where thepolymers are of compatible melt temperature).

[0107] Adaption member (81) is adapted to couple to internal valve (85)by inserting distal end portion of adaption member (81) which includesdistal adaption port (84) into valve inflation port (89). Preferably aseal at this adaption is accommodated with a suitable adhesive betweenadaption member (81) and the interior surface of internal valve (85)within valve inflation port (89) and neck (88), particular in the casewhere internal valve (85) is comprised of a material which is not heatcompatible with the heatshrink temperatures necessary for reconfiguringa heat memory polymer.

[0108] Another arterial catheter which includes a further internal valvevariation is shown in varied detail throughout FIGS. 4A-C. According tothis further variation, an expandable member coaxially surrounds theinner tubing which forms the internal flow lumen and expands inwardly tocollapse the internal flow lumen to the closed position. In moreparticular detail, the distal and proximal internal valves shown inFIGS. 4A-C are formed by coaxially securing pressure cuffs (106, 107),respectively, around inner tubing (102) and distally and proximallyadjacent to intermediate flow port (105), which is further shown toinclude a plurality of apertures extending between those pressure cuffs.Distal internal valve actuating lumen (108) and proximal internal valveactuating lumen (109) are shown distally coupled to the distal andproximal internal valves, respectively, and extend proximally therefromto a proximal end portion of the elongate body (101) where they areadapted to couple to a pressurizeable fluid source (not shown).

[0109] Further to the detail show in FIG. 4B, inner tube (102) iscollapsible within the pressure cuffs (106′, 107′) to form distal andproximal internal valves (106, 107) such that the collapsed walls withinthose cuffs substantially occlude internal flow lumen (102′) at thoselocations. More particularly regarding distal internal valve (106), thecoaxial space between pressure cuff (106′) and inner tube (102) is shownpotted at each end of pressure cuff (106′) with a suitable adhesive tocreate a seal. Further to the variation shown for proximal internalvalve (107), pressure cuff (107′) is comprised of a heat shrink tubing,such as has been previously herein described, which has been expandedand then shrunk at its ends to form the seal around the inner tubing. Ineither the adhesive or heat-shrink seal variation, the relativelycoupled actuating lumen is engaged within the outer pressure cuff priorto sealing the ends of the cuff to the inner tubing, such that the finalsealed internal valve is in fluid communication with a pressurizeablefluid source as a valve actuator.

[0110] For the purpose of further illustration, each of FIGS. 4B-C showsdistal internal valve (106) after being pressurized and adjusted to aradially expanded condition which characterizes the closed position,wherein inner tube (102) is shown collapsed to occlude flow throughinternal flow lumen (102′). Proximal internal valve (107) isalternatively shown in the open position wherein internal flow lumen(102) is open and patent for fluid flow. Moreover, to the extent thatthe coaxial space between the inner tube (102) and the outer cuff ateither internal valve is expanded inwardly into internal flow lumen(102′) during pressurization, this internal valve variation is hereinconsidered a coaxial balloon variation.

[0111] One particular luminal design for the “coaxial balloon” internalvalve embodiment just described is shown in various sectionalperspective and transverse cross-sectional views, respectively, in FIGS.4A and 4C. In general, outer tubing (103) coaxially surrounds andbundles inner tube (102) which forms internal flow lumen (102′),pressure cuffs (106′, 107′) which form internal valves (106, 107),distal and proximal internal valve actuating members (108, 109) whichform distal and proximal internal valve actuating lumens (108′, 109′),external shunt valve actuating member (110) which forms external shuntvalve actuating lumen (110′), and cardioplegia delivery and ventricularventing member (111) which forms cardioplegia delivery lumen (111′) andleft ventricular venting lumen (111″) (actual lumens formed by theindividual tubing members are shown only in FIG. 4C).

[0112] This bundled construction just described for the arterialcatheter of FIGS. 4A-C may be formed according to the heat shrinkbundling process variations previously described herein. Moreover, theparticular valve structures described and shown by reference to FIGS.4A-4C should not be limited to the specific luminal construction shownin variously throughout those Figures.

[0113] Still a further arterial catheter variation is shown in FIG. 5A,wherein only one distal internal valve (126) is shown within theinternal flow lumen (122′) distally of intermediate flow port (125).This variation shown is exemplary of one aspect wherein fluid withininternal flow lumen (122′) proximally of intermediate flow port (125) isbelieved to function as a virtual proximal internal valve in the closedposition. According to this variation, antegrade aortic blood flowingproximally through internal flow lumen (122′) from distal flow port(124) is not allowed to pass through the internal lumen proximally ofintermediate flow port (125) when there is a static head of fluid withinthat proximal lumen. That static head is provided when the proximallumen is filled with the fluid and the proximal flow port (not shown) isclosed. Rather, the shunted antegrade aortic flow travels out of thecatheter through intermediate flow port (125). Further to the singleinternal valve aspect of the FIG. 5A variation, the fluid used to fillthe proximal portion of internal flow lumen (122′) is preferably anisotonic and non-thrombogenic fluid, and more preferably is an isotonicsaline or ringer's lactate solution. To the extent that such solutionpassively mixes with aortic blood near intermediate flow port (125), itmay be desirable to periodically flush the proximal flow lumen throughintermediate flow port (125) with additional, fresh fluid in order toclear that mixed blood component from the static column in the lumenproximally of intermediate flow port (125).

[0114]FIG. 5A also shows a particular variation for external shunt valve(140) which, similar to the particular variation shown previously inFIG. 3B, is a relatively non-compliant variation of an expandableballoon which is reverted at its distal adaption to inner tube (122)which forms internal flow lumen (122′). In one method of forming theeverted adaption, a balloon subassembly (not shown in detail in FIG. 5A)includes an expandable working length bordered on either end by twooutwardly extending cuffs of reduced outer diameter. One of theoutwardly extending cuffs is sealed around the distal end portion of theinner tube (122), thereby forming a first adaption, such that theballoon's working length extends distally therefrom. The majority of theballoon's working length is thereafter turned inside out and rolledproximally over the first adaption, until the second outwardly extendingcuff is inside-out and faces proximally over the catheter shaft. Theportion of the balloon's working length which is not turned inside outor rolled proximally over the first adaption is ultimately the regionwhich forms at least a portion of funnel (142), and at least theeverted, proximally extending portion of that working length formsanchor (141). A second adaption is then made between the second cuff andthe inner tube (122), although proximally of an inflation port (128′)through which external shunt valve actuating lumen (128) communicateswith the interior chamber formed by external shunt valve (140). Theconstruction for elongate body (121) which forms the luminalconfiguration for catheter (120) is also shown in FIG. 5A, and also inadditional detail in the transverse cross-sectional view throughelongate body (121) in FIG. 5B. In this variation, elongate body (121)includes a multi-lumen extrusion which forms internal valve actuatinglumen (127), external shunt valve actuating lumen (128), andcardioplegia delivery and ventricular venting lumens (129, 130),respectively. The particular variation shown for external shunt valveactuating lumen (128) actually includes two lumens which are positionedside-by-side along the circumference of the extrusion which forms largerinternal valve actuating lumen (127). This particular variation isbelieved to optimize total luminal cross-section in order to rapidlyfill and evacuate external shunt valve (140) of fluid for rapidinflation and deflation, respectively, while further minimizing thecontribution of the total luminal cross-section to the outer diameter ofthe overall shaft assembly. Further to the multi-lumen extrusion, theindividual lumens formed thereby may be cut-away for suitable adaptionswhere desired according to the other previous described multilumenextrusion embodiments.

[0115] FIGS. 5A-B further show inner tube (122) as it is housedcoaxially within internal valve actuating lumen (127) and extendsdistally therefrom where it terminated in distal flow port (124). Innertube (122) is also laminated along a relatively thin-walled interiorsurface of a large round lumen of the multilumen extrusion at a regionalong the circumference of elongate body (121) opposite external valveactuating lumen (128). This lamination may be formed, for example, byplacing an electrically conductive mandrel (not shown), such as a tefloncoated stainless steel mandrel, through inner tube (122), forcing innertube (122) with the mandrel to press against the relatively thin-walledinterior surface, and then heating the mandrel such as by inductionheating in order to melt the inner tube (122) to that relativelythin-walled inner surface. In this manner, a continuous space is leftopen between inner tube (122) and the coaxial lumen within which innertube (122) is housed to thereby form internal valve actuating lumen(127). Further to the resultant actuating lumen, a seal is required inits distal end portion in order to pressurize that lumen for closinginternal valve (126), and is shown as a heat seal in FIG. 5A at thedistal region of the actuating lumen within external shunt valve (140).However, it is also further contemplated that that seal may be formed inother manners, such as for example by potting the lumen in adhesive.

[0116] Internal valve (126) is further shown in FIG. 5A to be arelatively collapsible portion of inner tube (122) and may beconstructed according to several variations. In one particular variationfor internal valve (126), inner tube (122) has variable thickness and isthinner at the region forming internal valve (126) where it iscollapsible at a lower pressure than the rest of inner tube (122). Inanother variation, inner tube (122) has variable material constructionalong its length, wherein a more flexible and collapsible material isprovided in the region forming internal valve (126). Further to thisvariation, inner tube may be formed generally of a high densitypolyethylene tubing but for the region forming internal valve (126),wherein a more collapsible tubing such as a low density polyethylenetubing is spliced into continuous member forming inner tube (122). Stillfurther to the variable flexibility version, inner tube may be a fiberreinforced composite, such as one containing a wire reinforcing coil orbraid within a polymeric matrix, again but for the region forminginternal valve (126) which is void of the reinforcing member and istherefore more amenable to collapsing under pressure. FIG. 6 shows stilla further internal valve variation, wherein cannula (144) is slideablyengaged within internal flow lumen (146′) and provides internal valve(145) internally of that flow lumen (146′), rather than integrating theinternal valve in a fixed arrangement along the elongate body ofarterial catheter (143). According to this arrangement, the internalvalve has variable positioning along internal flow lumen (146′) and canbe positioned for example at the following locations: distally of flowport (147), as shown at (145′); between flow port (147) and flow port(148), as shown at (145″); or proximally of flow port (148), as shown at(145″).

[0117] Still further to FIG. 6, internal valve (145) is further shown inthis variation as an expandable balloon which is adjustable from aradially collapsed condition, which characterizes the open position andwhich allows the cannula (144) to be slideably positioned andrepositioned within internal flow lumen (146′), to a radially expandedcondition which characterizes the closed position. Moreover, the balloonwhich forms internal valve (145) is also adapted to radially expand toone side of cannula (144). This design biases cannula (144) toward oneside of the tubing which forms internal flow lumen (146′), therebyclosing the internal flow lumen (146′) with the balloon whilemaintaining cannula (144) in a relatively straight condition along theside of the internal flow lumen (146′) in order to minimize hemodynamicaffects that cannula may have on the flow through that flow lumen.Furthermore, it is believed that the internal flow lumen according tothis design may be required to have a larger internal diameter in orderto make up for the presence of cannula (144) and accommodate therequired amount of flow therethrough. However, while internal flow lumen(146′) may be enlargened for this purpose, the valve and actuatingstructures for the internal valve are no longer built into the elongatebody of the arterial catheter and therefore the overall profile of theassembly may not be detrimentally increased. Still further to theparticular design shown in FIG. 6 for internal valve (145), otherdesigns than a balloon may also be interchangeably constructed accordingto the other previously described internal valve embodiments asappropriate, such as for example according to other expandable memberdesigns.

[0118] Moreover, cannula (144) according to the FIG. 6 embodiment may beone fixed cannula which provides the left ventricular venting lumen andcardioplegia lumen, in addition to an inflation actuating lumen forinternal valve (145). Or, in the alternative, cannula (144) may providean inflation actuating lumen for internal valve (145) and anotherthrough lumen through which one or two separate slideably cannulas, suchas cannula (149) shown in FIG. 6, may be engaged in order to provide theventricular venting and cardioplegia delivery functions. According tothis last arrangement, the internal valve may be desirably positionedwithin the internal flow lumen in order to provide the desired flowthrough the predetermined port or ports, while the cardioplegia deliveryand left ventricular venting ports, such as ports (149′, 149″),respectively shown in FIG. 6, may be separately positioned through theother slideably engaged cannula or cannulas.

[0119] In a further embodiment (not shown) to the “internal valve on aslidable cannula” variations just shown and described by reference toFIG. 6, the slidable cannula with the expandable member of the internalvalve may alternatively be positioned within a passageway or lumen whichis adjacent to the tubing which actually forms the flow lumen throughthe catheter, rather than actually positioning these elements within theflow lumen itself. According to this further variation, the tubingforming the internal flow lumen may be a flacid material which distendsfor relatively unrestricted flow under blood pressure while the valve isin the open position, and which is otherwise collapsible to occlude flowwhen the valve is in the closed position. Still further, the tubingforming the flow lumen may be an elastomeric tubing which elasticallyadjusts between collapsed and open conditions for flow according to therespective closed and open positions for the valve. These alternativeconstructions according to this variation are further developed above.

[0120] A further alternative external shunt valve variation to thatshown and described by reference to FIG. 5A is shown in various detailand modes of operation throughout FIGS. 7A-D. According to thisvariation, the expandable balloon is comprised of a fiber reinforcedcomposite which includes a predetermined, patterned mesh of relativelynon-compliant fibers which are imbedded or laminated within a matrix ofa relatively compliant polymeric material. A controlled and variedpattern of the reinforcing fibers along the length of the balloon isused to vary the longitudinal compliance along the balloon's length suchthat the funnel for the balloon valve is formed during inflation of theballoon.

[0121] More specifically, FIG. 7A shows external shunt valve (170) in aradially collapsed condition along the distal end portion of elongatebody (151) of arterial catheter (150). External shunt valve (170)includes a proximal portion (171), a distal shoulder (172), and a distaltaper (173). Proximal portion (171) and distal taper (173) each includesimilar radially oriented fibers (175) and also longitudinal fibers(176), whereas distal shoulder (172) includes similarly radiallyoriented fibers (175) and does not include longitudinal fibers. Thelongitudinal fibers (176) in proximal portion (171) and distal taper(173) are relatively non-compliant and allow for little or nolongitudinal compliance to the composite balloon skin in those regionsduring inflation. The radially oriented fibers (175) are also relativelynon-compliant, but have both a longitudinal and also a radial componentto their angled orientation. Due to this angled orientation for radiallyoriented fibers (175), some of both the radial and also the longitudinalcompliance of the matrix polymer is maintained for the composite balloonskin despite the presence of these fibers. A progression of balloonexpansion for the engineered composite variation just described is shownby comparing FIG. 7A, which shows the radially collapsed condition forexterior shunt valve (170), to FIG. 7B, which shows external shunt valve(170) in the radially expanded condition for the valve. This progressionfurther illustrates the fiber reinforced composite variation as it formsthe funnel in the shunting position according to external shunt valve ofthe present invention. As is shown in FIG. 7A, proximal portion (171),distal shoulder (172), and distal taper (173) have lengths L1, L2 andL3, respectively when the external shunt valve (170) is in the radiallycollapsed condition. Observing the relative lengths L1′, L2′, and L3′for the radially expanded condition shown in FIG. 7B, only distalshoulder length L2′ is longer than distal shoulder length L2 due to theunique ability for distal shoulder (172) to strain longitudinally underthe stress of the inflation pressure within the balloon. This variablelongitudinal strain between the distal shoulder (172) and distal taper(173) produces the funnel, which is shown in further cross-sectionaldetail in FIG. 7C. However, because all regions of the balloon havesubstantially the same radial or circumferentially oriented fiberreinforcement from fibers (175), including distal shoulder (172), it isbelieved that a relatively constant radial compliance and thereforeexpanded outer diameter is provided along the working length of theballoon between the tapers, as is further shown in FIG. 7B.

[0122] For the purpose of further illustrating the broad functionalaspects of the various particular arterial catheter embodiments justprovided with reference to FIGS. 2A-6C, various views of one particulararterial catheter variation is shown throughout FIGS. 8A-D duringvarious modes of use. FIG. 8A shows arterial catheter (180) with anexternal shunt valve (190) in a radially collapsed condition whichcharacterizes the open position for the valve. FIG. 8B provides aperspective view of arterial catheter (180) with the external shuntvalve (190) adjusted to the radially expanded condition whichcharacterizes the closed position for the valve. Detailed modes foradjusting the internal valves within arterial catheter (180), duringradial expansion of external shunt valve (190) in the closed position,are shown in FIGS. 8C-D.

[0123]FIG. 8C shows arterial catheter (180) during one operational modewhich is adapted to shunt antegrade aortic blood flow from the aorticroot (distally to the expanded external shunt valve), through aninternal flow lumen within the catheter, and out of that flow lumen andinto the systemic arterial circulation at a proximal region of theaortic artery. According to this mode, distal internal valve (186) is inthe open position and proximal internal valve (187) is in the closedposition. Antegrade aortic blood is depicted by arrows as it enters thefunnel (192) formed by external shunt valve (190), through distal flowport (183), along internal flow lumen (182), and out intermediate flowport (185) proximally of external shunt valve (190). The same arterialcatheter (180) is further shown in FIG. 8D after adjusting the externaland internal valves to another predetermined combination of theirrespectively open and closed positions such that the catheter is adaptedto isolate the systemic arterial circulation from the aortic rootdistally to the external shunt valve (190) and also distally of thedistal internal valve (186) within internal flow lumen (182). Thevalving configuration of FIG. 8D further adapts arterial catheter (180)to provide retrograde flow of oxygenated blood from a cardiopulmonarybypass pump (not shown), distally through the internal flow lumen (182),and into the systemic circulation proximally of the external shunt valve(190). This combination of valve adjustments is shown to includeadjusting external shunt valve (190) to the shunting position, distalinternal valve (186) to its closed position, and proximal internal valve(187) to its open position.

[0124] A second intermediate flow port (184) is also shown in shadow inFIGS. 8C-D and is optionally provided according to the arterial cathetermodes herein described. Concomitant with the inclusion of secondintermediate port (184), proximal internal valve (187) becomes anintermediate internal valve by virtue of its position between theadjacent pair of intermediate flow ports (185, 184). Proximal internalvalve (187′) is thus provided proximally of second intermediate flowport (184), as is shown in shadow in FIGS. 8C-D. The inclusion of secondintermediate flow port (184) in the perfusion of oxygenated bloodthrough the catheter is shown in both the antegrade aortic flow andretrograde bypass flow scenarios with dashed lined arrows in FIGS. 8C-D,respectively. As was previously described, the antegrade aortic flowthrough both intermediate flow ports as shown in FIG. 8C is achieved byclosing proximal internal valve (187′) and opening distal internal valve(186) and proximal internal valve (187), which in this case is actuallyan intermediate internal valve. The alternative blood perfusion from thebypass pump as shown in FIG. 8D is permitted through the secondintermediate flow port by opening proximal internal valve (187′) andeither closing proximal internal valve (187), which isolates perfusionflow through only the second intermediate flow port (184), or openinginternal valve (187) and closing distal internal valve (186), whichperfuses the blood from the pump through both the intermediate flowports (185, 184).

[0125] Venous Catheter

[0126] The venous catheter modes herein described are generally adaptedto isolate the right heart from vena caval blood flow and to aspiratethat flow into a cardiopulmonary bypass pump without circumferentiallyengaging the interior wall of the vena cavae. Specific embodiments areshown and described in detail in FIG. 9 and FIGS. 10A-D.

[0127] One venous catheter variation which is adapted to substantiallyisolate the right heart chambers from the venous flow in the vena cavaeand which achieves this isolation without engaging the walls of the venacavae is shown during use in a vena cavae in FIG. 9. More specifically,venous catheter (200) includes an elongate body (201) which includes adistal flow port (203) located along the elongate body's distal endportion and an intermediate flow port (205) located along the distal endportion proximally of distal flow port (203). A distal external valve(220) is located along the distal end portion proximally adjacent todistal flow port (203), while an intermediate external shunt valve (230)is positioned distally adjacent to intermediate flow port (205).

[0128] Each of the distal and intermediate external valves (220, 230)shown in the FIG. 9 variation is adjustable from a radially collapsedcondition, which characterizes an open position, to a radially expandedcondition, which characterizes a closed position. The respective openpositions for these valves are adapted to allow for percutaneoustransluminal delivery of the elongate body's distal end portion into theregion of the vena cavae adjacent to the sinus venarum in the rightheart, and is also adapted to allow for venous blood flow to pass fromthe superior and inferior vena cava and into the right heart chambersthrough the sinus venarum or vena caval inlet where the vena cavaecommunicate with the right atrium. The alternatively closed positionsfor the distal and intermediate external valves (220, 230) is adapted tosubstantially isolate the right heart chambers from vena caval bloodflow and aspirate that flow into a cardiopulmonary bypass pump, as isdescribed in more detail below.

[0129]FIG. 9 shows each of the distal and intermediate external valves(220, 230) in the radially expanded condition which characterizes itsrespective closed position. Each of the valves in the radially expandedcondition has a working length with an outer diameter which is slightlyless than the inner diameter of the superior vena cava, in the case ofdistal external valve (220), or the inferior vena cava, in the case ofintermediate external valve (230). This relationship is shown forexample in FIG. 9 by comparing distal external valve outer diameter ODwith superior vena cava inner diameter SVC ID. The closed position forthe valves therefore does not completely occlude the relative vena cava,but instead only substantially occludes the vessel lumen and therebyincreases the pressure upstream of the respective valve. By positioningeach valve downstream and adjacent to a flow port into an internal lumenof the catheter, the increased pressure due to the valve expansionthereby increases the pressure adjacent to the adjacent flow port andenhances aspiration of blood through that port and into the respectivelycoupled internal flow lumen. The aspirated blood further travelsproximally along the flow lumen, out of the lumen through a proximalflow port (not shown), and into a cardiopulmonary bypass pump, shownschematically at cardiopulmonary bypass pump (250), which may be anysuitable pump such as the “BioPump” described above, according to one ofordinary skill.

[0130] The external valves shown and described for the venous cathetervariation of FIG. 9 therefore do not completely isolate the right heartchambers from vena caval blood, but instead do so only substantially bycreating a significant occlusion to flow into those heart chambers andaspirating the blood with suction from an external pump at a locationopposite that artificial occlusion from the heart. However, it iscontemplated that the “substantial” aspiration of blood and“substantial” isolation of the heart may still provide some degree ofleakage of vena caval blood around the external valves and into theheart.

[0131] Further to the external valve leakage just described, a leakageflow port (207) is further shown in FIG. 9 between distal external valve(220) and intermediate external valve (230). Leakage flow port (207)enhances additional aspiration of the blood which might leak around thedistal and intermediate external valves (220, 230) and into the regionof the vena cava adjacent to the sinus venarum.

[0132] It is believed that each of the distal, intermediate, and leakageflow ports (203, 205, 207) preferably communicate proximally to thecardiopulmonary bypass pump via independent and separate flow lumens.For example, a distal flow lumen (not shown) may fluidly couple a distalflow port (203) to a proximal flow port (not shown) which is coupled tocardiopulmonary bypass pump (250)(proximal flow port coupling shownschematically), an intermediate flow lumen (not shown) may fluidlycouple intermediate flow port (205) to cardiopulmonary bypass pump(250), and a leakage flow lumen (not shown) may couple leakage flow port(207) to cardiopulmonary bypass pump (250). Further to such a multiplevenous aspiration luminal design, it is further believed that a highernegative pressure may be desirable at the the distal flow port (203)than the other ports. Moreover, another acceptable variation provides acommon internal flow lumen (not shown) between distal and intermediateflow ports (203, 205), with a separate independent flow lumen (notshown) coupled to leakage flow port (207).

[0133] According to this latter variation, the blood which leaks aroundand between distal and intermediate external valves (220, 230) and whichis adjacent to leakage flow port (207) is at a significantly lowerpressure than the blood adjacent the distal and intermediate flow ports(203, 205) on the upstream side of either of external valves (220, 230),respectively. If leakage flow port (207) were coupled to the sameinternal flow lumen as distal or intermediate flow ports (203, 205),such a coupling may provide a shunt around the external valves and causean undesirable flow of blood from the high pressure zones adjacent todistal and intermediate flow ports (203, 205), through the commoninternal flow lumen, and outwardly into the low pressure zone throughleakage flow port (207). By segregating the internal flow coupled toleakage flow port (207) from the internal flow lumen coupled to theother high pressure flow ports, the relatively low pressure flow isisolated from the relatively high pressure flow.

[0134] Further to the FIG. 9 variation, it is further contemplated thatdistal external valve (220) may be provided at the exclusion ofintermediate internal valve (230). The venous blood pressure in theinferior vena cava is lower than that in the superior vena cava, and itis believed that the blood in the inferior vena cava may be sufficientlyaspirated merely through applied suction from the external pump atintermediate flow port (205). In the higher pressure zone at thesuperior vena cava, however, it is believed that at least a partiallyocclusive cuff such as distal external valve (220) may be required inorder to prevent unacceptably high volumes of blood from flowing pastthe distal flow port (203) and entering the right heart chambers.

[0135] For the purpose of further illustrating the use of venouscatheter (200) in a minimally invasive cardiac bypass system, FIG. 9further shows cardiopulmonary bypass pump (250) schematically coupled toarterial catheter (260) via an outlet port (not shown) on the pump.Arterial catheter (260) is generally adapted to isolate the left heartchambers from systemic arterial circulation while perfusing oxygenatedblood from the cardiopulmonary bypass pump (250) into that circulation.Furthermore, arterial catheter (260) may comprise one of severalconventionally known catheters for this purpose, or may include one ofthe several arterial catheter embodiments previously described above. Inaddition, FIG. 9 also schematically shows the proximal end portion ofvenous catheter (200) as it is proximally coupled to an external valveactuator (240). External valve actuator (240) is adapted to adjust theexternal valves along the distal end portion of the catheter betweentheir relative open and closed positions. External valve actuator (240)may be specifically adapted as one pressurizeable fluid source adaptedto switch actuation between the external valves, in the case ofexpandable balloon variations provided at the external valves, oralternatively as two such fluid sources, as has been previouslydescribed above for adjusting multiple balloons as internal valves.

[0136] The present invention according to the FIG. 9 variation furthercontemplates other designs for external valves along the venous catheterbody which are adapted to substantially isolate the right heart chambersfrom vena caval blood flow without circumferentially engaging theinterior wall of the vena cavae. For example, in one further vena cavalexample (not shown), regions along the distal end portion of theelongate body for the venous catheter may include suction ports whichare adapted to provide sufficient negative pressure adjacent to the venacaval wall that the wall collapses down around the elongate body at thatregion. This “suction region” may have a larger outer diameter than theother portions of the venous catheter in order to minimize the extent towhich the vena caval wall must collapse. Furthermore, such a “suctionregion” may also be expandable to an expanded outer diameter whichapproaches the inner diameter of the vena caval wall, although fallingshort of actually engaging the wall. Upon collapsing the vena caval wallonto the body surface adjacent to the ports along the suction region,the expandable section may remain at the expanded outer diameter, or mayalternatively be reduced in its outer diameter, bringing the vena cavalwall further downward to a reduced diameter.

[0137] The endolumenal venous isolation catheter (200′) shown in FIG. 9Bincludes distal and proximal external valves (220′, 230′) which areadjustable relative to each other's position along catheter (200′). Inparticular, distal external valve (220) is provided on inner member(201′) whereas proximal external valve (230) is provided on outer member(201″) that is slideably disposed over internal member (201′). Byproviding indicia of the relative positions of distal and proximalexternal valves (220′, 230′), their spacing may be adjusted to match aparticular patient's anatomy. In particular, a physician may adjust thisspacing based upon the observed anatomy at the interface between thevena cavae and the right atrium, such as for example according to anX-ray, magnetic resonance, ultrasonic or optical views of this area.According to this adjustable valve variation, blood may be aspiratedfrom the superior and inferior vena cavae through ports (203′, 205′),respectively, and transported into a cardiopulmonary bypass system viaseparate aspiration lumens (not shown) provided along inner and outermembers (201′, 201″), also respectively. Exterior valves (220′, 230′)may be adapted to substantially occlude the great veins withoutexpanding and engaging the wall of the veins, as previously describedabove, in which case an intermediate port may also be provided forvenous blood aspiration between the external valves, as shown at (207′).However, it is also further contemplated that such valves may beexpandable members such as balloons which actually engage the walls ofthe great veins during use, as shown in FIG. 9B.

[0138] Another alternative venous catheter variation to that shown inFIG. 9 is shown in FIGS. 10A-D, wherein venous catheter (250) is shownin various modes of operation as it is adapted to isolate a rightventricle from vena caval flow without engaging the interior walls ofthe vena cavae.

[0139] As shown in FIG. 10A, venous catheter (250) includes an externalvalve (260) along the distal end portion of elongate body (251) betweendistal and proximal flow ports (254, 256). External valve (260) includesa valve member (262) which is positioned at a discrete location aroundthe circumference of elongate body (251) and is shown in FIG. 10A in afirst radial position which characterizes the open position for externalvalve (260). In the particular variation shown, valve member (262) inthe first radial position is housed within a recess (258) provided atthe discrete location along the elongate body's circumference. In thisopen position, external valve (260) is therefore adapted to facilitatepercutaneous transluminal delivery of the distal end portion of elongatebody (251) into the region of the vena cavae adjacent to the sinusvenarum, and is further adapted to allow for venous flow to perfusearound the elongate body's distal end portion and into the right heartchambers.

[0140] Distal and intermediate flow ports (254, 256) are coupled to atleast one internal flow lumen which extends through the catheter andterminates proximally in a proximal flow port which couples to an inletport of a cardiopulmonary bypass pump (not shown). Any one of severalvariations for coupling these ports to the proximal pump may besuitable, as was previously described by reference to the prior venouscatheter shown in FIG. 9. FIG. 10B shows venous catheter (250) in afurther operational mode, wherein valve member (262) has been adjustedfrom the first radial position to a radially displaced position which isadjacent to the outer surface of elongate body (251). When the discretelocation of valve member (262) is positioned within the vena cavae andadjacent to the sinus venarum into the right atrium, the radiallydisplaced position for valve member (262) is adapted to place valvemember (262) within the right atrium, preferably at or adjacent to thetricuspid valve which separates the right atrium from the rightventricle.

[0141] Valve member (262) is further shown in FIGS. 10A-B to include twoexpandable members (264, 266), which are each adjustable from a radiallycollapsed condition (shown in FIGS. 10A-B) to a radially expandedcondition. Expandable members (264, 266) are further shown in FIG. 10Cto be coupled to expandable member actuators (271, 272). In theparticular variation shown variously throughout FIGS. 10A-B, expandablemembers (264, 266) are balloon members which are adjusted to theradially expanded position by pressurizing their inner chamber withfluid. Such balloon construction may be of the relatively compliant typeor of the relatively non-compliant type, as have been describedpreviously above. According to the expandable balloon variation,expandable member actuators (271, 272) therefore comprise luminalpassageways which are adapted to couple to at least one pressurizeablefluid source (not shown) for inflating the respectively coupled balloonor balloons. It is contemplated that either one such pressurizeablefluid source may be coupled to both expandable members (264, 266), orseparate such sources may be provided for individually actuating eachexpandable member (264, 266), respectively.

[0142]FIG. 10C further shows expandable members (264, 266) separated bya space S. This separation may be a fixed relationship between themembers, or may be adjustable. One variation of the latter adjustablearrangement is shown in FIG. 10C, wherein expandable members (264, 266)are independently adjustable and movable relative to the other bymanipulating the respectively coupled expandable valve actuator. Onesuitable construction for this adjustable separation variation for theexpandable members may provide a groove through or around expandablemember (264) so that expandable member actuator (272) may slideablyextend through the groove to adjust the positioning of the more distallydisposed expandable member (266). In another construction, expandablemember actuator (272) may be coaxially disposed within expandable memberactuator (271) and also within and through expandable member (264).

[0143] In one more particular variation of this latter construction (notshown), expandable member actuator (271) is preferably constructed of aninner member coaxially disposed within and extending distally beyond anouter member. Expandable member (264) is sealed at its proximal end uponthe outer member and at its distal end upon the inner member. Thecoaxial space between the inner and outer member provides the inflationlumen for expanding expandable member, whereas the inner lumen formed bythe inner member forms an inner conduit through which expandable memberactuator (272) may slideably extend through and distally beyond forcoupling to expandable member (266).

[0144] The distal end portions of expandable member actuators (271, 272)must advance along and bend through a substantial angle while adjustingthe valve member (262) from the first radial position shown in FIG. 10Ato the radially displaced position shown in FIGS. 10B-D. Therefore,these actuators are preferably highly flexible, and comprise for examplehighly flexible polymeric tubing for the expandable member balloonvariation shown. Examples of acceptable materials for constructing theseactuator tubings include for example: low modulus polyurethane, PEBAX,low or linear low density polyethylene, nylon, and polyvinyl chloride.In order to achieve the requisite pushability and remote maneuverabilityof the distal end portions, however, the proximal end portions ofexpandable member actuators (271, 272) (not shown) may be preferablyconstructed of stiffer materials, such as for example high densitypolyethylene, high modulus polyurethane, polyester terepthalate,polyimide, or metal hypotube materials, in order to allow for distaladvancement of those members through elongate body (250) such thatexpandable members (264, 266) for valve member (262) may be adjusted tothe relatively displaced positions described.

[0145]FIG. 10D shows expandable members (264, 266) during still afurther mode of operating venous catheter (250) and after being adjustedfrom the radially collapsed condition shown in FIGS. 10A-C to a radiallyexpanded condition. This radially expanded condition of expandablemembers (264, 266) substantially reduces or closes the space S betweenthose members (shown in FIG. 10C), and is adapted to engage thetricuspid valve when positioned within that space prior to expanding theexpandable members.

[0146] Therefore, according to the progressive modes of operation shownfor particular venous catheter (250) in FIGS. 10A-D, the closed positionfor the external valve (260) is characterized by: (1) aligning thediscrete location of valve member (262), while in the first radialposition within recess (258), with the sinus venarum in the rightatrium; (2) adjusting valve member (262) from the first radial positionto the radially displaced position adjacent to elongate body (251) andat least in part within the right atrium and adjacent to the tricuspidvalve between the right atrium and the right ventricle; and (3)adjusting at least a portion of the valve member (262) from a radiallycollapsed condition to a radially expanded condition which engages thetricuspid valve and substantially isolates the right ventricle from thevena cava.

[0147] It is further contemplated that other venous catheter variationsthan those just shown and described by reference to FIGS. 9-9D maysuitably function as the venous catheter which is broadly adapted to:(a) substantially isolate the right ventricle from the venous bloodflow; and (b) substantially aspirate the vena caval blood into acardiopulmonary bypass pump; and wherein both the isolation and theaspiration functions are performed without circumferentially engagingthe interior wall of the vena cavae.

[0148] For example, in a further variation (not shown) of the externalvalve shown variously throughout FIGS. 10A-D, the valve member in theradially displaced position expands within the right atrium and fillsthat atrium to such an extent that either no blood or a negligiblevolume of venous blood is allowed to flow between the vena cavae and theright ventricle. In a further variation of the discretely located andradially displaced valve member, the valve member in the radiallyexpanded condition circumferentially engages a circumferential path ofatrial wall tissue which defines that atrium, thereby transecting theatrium such that the sinus venarum is isolated from the right ventricleby the expanded valve member. In still a further variation, the twoexpandable members are substantially provided as previously shown anddescribed by reference to FIGS. 10A-D, although are modified to insteadengage the internal valve and thereby isolate the right ventricle simplyby adjusting the individual members toward each other—in other words,the expandability of the expandable members may not be completelyrequired.

[0149] Minimally Invasive Bypass Catheter System

[0150] FIGS. 11-13 show one minimally invasive cardiac bypass systemwhich includes one combination of particular arterial and venouscatheter embodiments previously described above for the purpose offurther illustrating the sequential modes of use of a combinationassembly in performing a minimally invasive cardiac bypass procedure.For example, venous catheter (320) shown throughout FIGS. 11-13 isconstructed according to the particular embodiment previously shown anddescribed by reference to FIGS. 10A-D. However, other venous catheterembodiments such as that previously described by reference to FIG. 9 maybe alternatively suitable for use in the overall assembly shown in FIGS.11-13.

[0151] FIGS. 11-13 further show highly schematic representations for theaortic artery, superior and inferior vena cavae, and heart within whichthe catheters of the overall assembly are shown in various operablemodes. For example, there is no particular depiction of the left orright atria or ventricle, although the salient structures regarding theoperable catheter modes shown are provided schematically, including thesinus venarum and tricuspid valve in the right heart and the aorticvalve in the left heart.

[0152] More specifically, FIG. 11 shows the arterial and venouscatheters (301, 320) which make-up minimally invasive cardiac bypasscatheter system (300) during placement within their respectively desiredtarget vessels. Such percutaneous transluminal catheter placement may beperformed in-part according to the standard “Seldinger” technique oraccording to a direct “cutdown” method including an arteriotomy, aswould be apparent to one of ordinary skill. For the purpose of furtherillustration, however, the general access method according to the“Seldinger” technique is performed as follows.

[0153] First, a puncture is first made in the desired vessel forintroducing the subject catheter. Such an introduction site for thearterial catheter may be for example in a femoral or a subclavianartery, although preferably in the femoral artery, and for the venouscatheter may be for example in a femoral or jugular vein, althoughpreferably in a femoral vein. A guidewire is then advanced through thebore of the needle, after which the needle is withdrawn and a dilator isadvanced coaxially over the guidewire. By advancing a tapered distal endof the dilator through the puncture site, that wound is dilated open bythe taper until reaching a desired predetermined diameter. An introducersheath with a hemostatic valve is then advanced either over the dilatoror the guidewire or both, after which either the dilator or theguidewire or both are removed from the introducer. The subject device isthen advanced into the relative vessel coaxially through the introducersheath and hemostatic valve.

[0154] Each of the venous and arterial catheters is also adapted totrack over a steerable, radiopaque guidewire which is adapted to steerand select desired branched vessels under X-Ray visualization inpercutaneous transluminal procedures. Therefore, FIG. 11 shows arterialcatheter (301) and venous catheter (320) while tracking over guidewires(310, 315), respectively, and into the aortic arch and the region of thevena cavae adjacent to the sinus venarum of the right heart, alsorespectively. Each of guidewires (310, 315) may be coaxially positionedwithin the internal flow lumen and through the proximal and distal flowports of the respectively engaged catheter. Alternatively, each of theseguidewires may be slideably engaged within a common internal flow lumenwhich extends between and fluidly couples with a distal and intermediateflow port along the distal end portion of the respective catheter, suchas for example in “rapid-exchange” or “monorail” catheter designs whichare previously disclosed for use in angioplasty catheters. In stillanother alternative variation, the guidewires may be slideably disposedwithin separate guidewire tracking members extending throughout therespective arterial and venous catheters. Regardless of the particularcatheter coupling, however, any one of several known guidewire designsmay be suitable for use in positioning the catheters herein described,as would be apparent to one of ordinary skill.

[0155] Further to the positioning mode of operation shown in FIG. 11,both external shunt valve (303) and external valve (330) are shown intheir respectively closed positions which allow for the arterial orvenous blood to flow around the distal end portion of the respectivearterial and venous catheters (301, 320) and which also allow for thepercutaneous transluminal placement according to this mode. Further tothe placement of arterial catheter (301), the distal end portion ofelongate body (301) is placed within the aortic arch such that externalshunt valve (303) is positioned between the aortic root and the carotidarteries. The distal end portion of elongate body (322) for venouscatheter (320) is positioned such that distal flow port (324) andintermediate flow port (326) are positioned within the superior andinferior vena cavae, respectively, and such that valve member (332) forexternal valve (330) is aligned with the sinus venarum in the rightatrium.

[0156] In order to facilitate accurate positioning as just described forthe relative components along the distal end portions of the arterialand venous catheters, radiopaque markers may be provided at or adjacentto these catheter structures in order to use X-ray or fluoroscopicvisualization when guiding the catheters into place. In the alternativeor in addition to such radiopaque markers, markers or other indicia mayalso be provided on the proximal end portions of these catheters suchthat the catheters in vivo position is determinable when the catheter isobserved to advance a predetermined distance beyond an introducer sheathor guiding catheter according to the positioning of such proximalindicia relative to the introducer or guiding catheter. Moreover, otherpositioning means may be used in order to accurately place the relativevalves and flow ports of the arterial and venous catheters. For example,ultrasound visualization may be used to aid in accurate placement ofthese structures. In one ultrasound variation, an ultrasonic probe maybe used externally of one or both of these catheters, either along sideand adjacent to the catheter or even further removed location such as inthe esophagus in a transesophageal approach. Still further, direct fiberoptic imaging may be employed for visualizing the position of therespective catheter structures in relation to the particular anatomicalstructures of interest.

[0157]FIG. 12 shows a further mode of operation for each of arterial andvenous catheters (301, 320) during use within minimally invasive cardiacbypass system (300).

[0158] More specifically to arterial catheter (301) as shown in FIG. 12,exterior shunt valve (303) is shown in a radially expanded conditionwhich characterizes a shunting position for that valve within the aorticarch. Exterior shunt valve (303) in the shunting position forms anchor(304), which circumferentially engages the interior surface of theaortic wall, and also forms funnel (305) which directs antegrade aorticblood flow into distal flow port (306), proximally through an internalflow lumen (not shown) and out an intermediate flow port (307) which islocated along elongate body (302) proximally of external shunt valve(303). In this operable mode, arterial catheter (301) is thus adapted tosecure the distal end portion of elongate body (302) into position whileallowing the heart to continue beating and perfusing the systemicarterial circulation proximally of anchor (304). This shunted antegradeflow may be further facilitated by adjusting a distal internal valve(not shown) within the flow lumen distally to intermediate flow port(307) and a proximal internal valve (not shown) within the flow lumenproximally of intermediate flow port (307) to open and closed positions,respectively, as has been previously described above by reference to theparticular arterial catheter embodiments.

[0159] Further to the operable mode of arterial catheter (301) shown inFIG. 12, a distal cannula member is shown extending from elongate body(302) distally from external shunt valve (303) and distal flow port(307), and includes cannula delivery port (308) and ventricular ventingport (309). Cannula delivery port (308) is positioned within the aorticroot in the region of the sinus of valsalva and is fluidly coupled to apressurizeable cardioplegia agent source (not shown) via a cardioplegiadelivery lumen (also not shown), such as has been described previouslyabove. Ventricular venting port (309) is positioned through the aorticvalve and into the left ventricle where it is adapted to aspirateresidual blood from that ventricle during the cardiac bypass procedure.

[0160] Specifically regarding venous catheter (320) as shown in FIG. 12,valve member (332) is shown adjusted to a radially displaced positionadjacent to the elongate body (322) and within the right heart chambers.In more detail, two expandable members (334, 336) which comprise atleast in part valve member (332) are separated by a space which housesthe tricuspid valve located between the right atrium and ventricle.

[0161]FIG. 13 shows still a further operable mode for each of thearterial and venous catheters (301, 320) as they are used to bypass theheart subsequent to temporarily arresting the heart according to theoverall assembly herein described.

[0162] Arterial catheter (301) is shown in an operable mode where it isadapted to isolate the heart from systemic arterial circulation andprovide artificial flow of oxygenated blood into the systemiccirculation from the cardiopulmonary bypass pump (not shown). Accordingto this mode, cardioplegia agent is delivered into the coronary arteriesvia cardioplegia delivery port (308) and the heart is therebytemporarily arrested. With external shunt valve (303) still anchored inthe aortic arch in the shunting position, the internal lumen isselectively occluded with a distal internal valve (not shown) locatedwithin the lumen between the distal and intermediate flow ports (306,307) according to the operable mode shown in FIG. 13. Thus, the leftheart chambers are isolated from systemic arterial circulationproximally of external shunt valve (303) and the distal internal valvewithin the internal flow lumen. Arrows exiting intermediate flow port(307) are thus used in FIG. 13 to depict the artificial flow ofoxygenated blood distally through the internal flow lumen from acardiopulmonary bypass pump.

[0163] Venous catheter (320) is shown in FIG. 13 in an operable modewhich is adapted to substantially isolate the right heart chambers fromthe vena cavae and also to aspirate the venous blood in the vena cavaeinto the inlet port of the cardiopulmonary bypass pump. According tothis mode, the two expandable members (334, 336) are shown adjusted to aradially expanded condition which narrows the space of separationtherebetween and engages the tricuspid valve, thereby isolating theright ventricle from the right atrium and vena cavae. Arrows show venousblood as it is aspirated into the at least one internal flow lumen ofthe venous catheter and into a cardiopulmonary bypass pump (not shown).

[0164] Endolumenal Proximal Anastomosis Isolation Assembly

[0165] FIGS. 14A-23B variously show an endolumenal proximal anastomosisisolation assembly which is adapted to endolumenally isolate a proximalanastomosis site from a pressurized aortic blood field. As will bedescribed in more detail below, by use of this assembly a proximalanastomosis may be formed between a bypass graft and the aorta during abeating heart CABG procedure without significant loss of blood at theproximal anastomosis site. By general reference to FIGS. 14A-B, andFIGS. 22A-B, arterial catheter (400) is shown to include an elongatebody (402) with an aortic isolation assembly (410) along its distal endportion (404). Aortic isolation assembly (410) includes distal andproximal balloons (420, 440) which are spaced along the longitudinalaxis of the elongate body by an isolation region (430). Distal andproximal balloons (420, 440) are shown in FIG. 14A in first and secondradially collapsed positions, wherein these balloons have outerdiameters that are adapted to facilitate delivery of arterial catheter(400) into the aorta (470).

[0166] With isolation region (430) positioned along anastomosis site(472), as shown in FIGS. 14B and 22B, distal and proximal balloons (420,440) are adjustable to first and second radially expanded positions,respectively, which are shown to have expanded outer diameters which aresufficient to engage upstream portion (475) and downstream portion(477), also respectively, of aorta (470). As further shown in FIGS. 14Band 22B, elongate body (402) further includes a flow lumen (shownschematically by way of flow arrows) which extends at least in partbetween a distal port (404) and a proximal port (405) which is furthershown as a plurality of apertures (406). Distal port (404) is providedalong the distal end portion (403) of elongate body (402) distally ofdistal balloon (420), whereas proximal port (405) is provided alongdistal end portion (403) proximally of proximal balloon (440).

[0167] According to this construction for catheter (400) and thedeployed configuration shown in FIG. 14B and FIG. 22B, proximalanastomosis site (472) and isolation region (430) are substantiallyisolated from pressurized aortic blood in upstream and downstreamregions (475, 477) by means of radially expanded distal and proximalballoons (420, 440). With this isolation established, aperture (473) isalso shown after being formed along the proximal anastomosis site (472).By further reference to the positioning of distal and proximal ports(404, 405) relative to distal and proximal balloons (420, 440),respectively, the pressurized aortic blood is also shown schematicallyby way of flow arrows as it is shunted from the upstream region (475),into the flow lumen through distal port (404), proximally along the flowlumen, out from the flow lumen through proximal port (405), and intodownstream region (477).

[0168] Accordingly, a proximal anastomosis may thus be formed ataperture (473) during a beating heart CABG procedure without substantialloss of blood and without externally clamping the aorta. In addition, itis believed that the expandable balloons (420, 440) which provide theisolation along the anastomosis site furthermore provide a benefit insubstantially “stenting” the aorta into a distended, substantiallyphysiologic shape while the proximal anastomosis is being formed.

[0169] FIGS. 15A-B and 23A-B, show another arterial catheter (450) whichis adapted to isolate a proximal anastomosis site (472) during a beatingheart procedure, and illustrates another specific design for aortaisolation assembly (460). By contrast to the assembly shown in FIGS.14A-B and 22A-B, arterial catheter (450) shown in FIGS. 15A-B and 23A-Bincludes an aorta isolation assembly that includes only one balloon(461) having a shape when expanded that forms distinct distal andproximal regions (463, 469) which are separated by intermediate region(465) that is located along isolation region (462). More specifically,similar to distal and proximal balloons (420, 440) shown in FIG. 14A-Band 22A-B, distal and proximal regions (463, 469) of balloon (460) areexpandable to radially expanded positions having first and secondexpanded outer diameters that are sufficient to engage upstream anddownstream regions (475, 477) of aorta (470), respectively. Intermediateregion (465) is shown also expanded when the balloon is in the radiallyexpanded condition, except only to an outer diameter which issubstantially less than the outer diameters of the distal and proximalregions (463, 469) engaged to aorta (470) and insufficient to engageaorta (470) along the proximal anastomosis site (472). Accordingly, asimilar isolation of proximal anastomosis site (472) is achieved withthe FIG. 15B and FIG. 23B assembly as that shown in FIGS. 14B and 22B.Moreover, the limited range of expansion along intermediate region (465)of balloon (460) relative to proximal and distal regions (463, 469)allow aperture (473) to be punched at the isolated anastomosis site(472) and a graft to be sutured, stapled, or otherwise anastomosed therewithout compromising the inflated balloon (460).

[0170]FIGS. 14B and 15B also show in shadow view distal internal valves(406, 456), respectively, and proximal internal valves (407, 457), alsorespectively, in order to illustrate that the internal flow lumen of theassemblies in those Figures may be constructed to incorporate thevarious novel aspects of the cardiac bypass embodiments previouslydescribed above by reference to FIGS. 1A-8D and 11-13. For example,either of aorta isolation assemblies (410, 460) may also be used asshunt valves in a stopped-heart cardiac bypass procedure as previouslydescribed above merely by closing the flow lumens in the respectivecatheters with either of distal internal valves (406, 456),respectively. Moreover, the distal balloons shown for assemblies (410,460) include funneled distal shapes in a similar construction to thevarious embodiments provided above for the shunting cardiac bypassaspect of the invention, thereby enhancing the fluid dynamics ofpressurized blood flowing from the aortic root as it is shunted into theinternal catheter flow lumen. Accordingly, this combination constructionprovides one catheter which may provide endolumenal proximal anastomosisisolation in either a beating heart or a stopped heart procedure.

[0171] By referring to FIGS. 22A-23B another embodiment can be seen thatutilizes a movable internal valve member (2200) to control antegrade andretrograde blood flow in the internal lumen of elongate body (402). Themovable internal valve member may consist of an expandable region (2201)positioned at or near the distal tip (2203) of cannula (2204). As can beseen in FIGS. 22B and 23B, cannula (2204) is movable within the flowlumen and can be selectively positioned to permit endolumenal proximalanastamosis isolation in either a beating heart or stopped heartprocedure. The cannula (2204) can be advanced or retracted within theflow lumen to position expandable region (2201) proximally of apertures406 to permit antegrade flow from a beating heart; or positioneddistally of aperatures 406 to permit flow from the by-pass pump when theheart is stopped. The expandable region (2201) of cannula (2204) may bean inflatable balloon (2201′) which is expandable by a fluid deliveredthrough a delivery lumen (2206) contained within cannula (2204).

[0172] Although the expandable region as above described may be inflatedby a fluid to occlude the flow lumen, the expandable region may also beexpanded by a construction that includes an enclosed volume having afixed mass of fluid whose shape may be varied mechanically to extend theshape radially against the flow lumen wall so as to occlude the flowlumen. Such a mechanical system would eliminate the need for a deliverylumen to deliver fluid under pressure in order to inflate a balloon.

[0173] As can be seen in FIGS. 22A and 23B, the cannula may beexternally introduced into the flow lumen through a sealed connector(2207). Visualization of the expandable region (2201) for positioning itwithin the flow lumen may be accomplished by radiopaque and visiblex-ray fluoroscopy or the expandable region may be visualized by the useof ultra sound or other techniques well-known in the prior art.

[0174] One specific construction which is believed to be sufficient forforming a balloon such as balloon (460) just described by reference toFIGS. 15A-B is shown in FIG. 16. More specifically, FIG. 16 showsintermediate region (485) of balloon (480) to have a different materialconstruction than distal and proximal regions (483, 489) of balloon(480). In one aspect of this assembly, the intermediate region (485) maybe constructed to be less compliant than the distal and proximal regions(483, 489), thereby yielding the expansion characteristic with varyingouter diameters as shown. In one specific aspect of this variedcompliance, a series of different tubings constructed of differentmaterials may be spliced together to form balloon (480). Or, balloon(480) may be constructed at first of one continuous material along theseregions which is modified along the intermediate region (485) to yieldthe variable compliance along the balloon. In one aspect of such aconstruction, the balloon wall may be thicker along the intermediateregion (485) than at distal and proximal regions (483, 489). Also, theballoon material along either the intermediate region (485) or thedistal and proximal portions (483, 489) may be specially treated apartfrom the other regions, such as by radiation or chemical treatment, suchthat the material essentially changes its expansion characteristics.Furthermore, a composite construction may be provided along the balloon(480), such as for example by using reinforcement fibers similar to theconstruction previously shown and described by reference to FIGS. 7A-C,though modified in order to yield the shapes shown in FIGS. 16 and 15B.The fiber component according to the specific fiber-reinforced compositeconstruction just described for balloon (480) in FIG. 16 may beconsidered more broadly as an expansion limiter provided alongintermediate region (485). FIG. 17 shows another embodiment wherein anexpansion limiter (497) is provided along intermediate region (495) ofballoon (490), and more specifically shows the expansion limiter (497)as a cuff which is provided over intermediate region (495) of balloon(490). Such a cuff may be an elastic band simply placed overintermediate region (495), or may be a laminate layer secured tointermediate region (495) in order to modify the overall compliancealong that portion of the balloon (490). Moreover, such a cuff in anyevent may be provided externally of intermediate region (495), or in analternative construction may be laminated onto an inner surface ofintermediate region (495).

[0175] The particular balloon embodiments shown in FIGS. 14A-23B arespecific illustrations of a more general construction contemplated forthe aorta isolation assembly herein described. In this regard, the aortaisolation assembly provides distal and proximal portions which areseparated by an isolation region. The “inflated” or “expanded”conditions shown for the balloon embodiments in FIGS. 14B, 15B, 22B and23B may be illustrated more broadly in that the distal and proximalportions of the assembly are adjustable to “extended” positions whichare extended from the shaft to engage the aorta. As such, otheralternative “expandable” or otherwise “extendible” members may besubstituted for these specific balloon embodiments herein specified. Inaddition, it is also to be appreciated that the distal and proximal“portions” of an aortic isolation assembly such as according to thespecific embodiments herein shown and described may be adjusted to theirrespective extended positions either together or separately. Forexample, the distal and proximal balloons (420, 440) shown in FIGS. 14Band 22B may be either fluidly coupled to separate pressurizeable fluidsources (425, 445) and thus be inflated separately, or may be coupled toa common pressurizeable fluid source. Such common coupling betweenpressurizeable fluid source (425) and distal and proximal balloons (420,440) may be achieved via either one common inflation lumen between theballoons, or by separate lumens coupled to the common inflation source,such as shown schematically at lumens (426, 446′). Similarly, the distaland proximal regions (463, 469) for balloon (460) shown in FIGS. 15B and23B may also be constructed in such a way as to be effectively expanded“separately”, such as by varying the construction between these regionsin a similar manner described by reference to the intermediate regionsof the embodiments shown in FIGS. 16 and 17.

[0176] Also, visualization markers are variously shown throughout FIGS.14A-17 positioned over a tubular member along the isolation region ofthe respective aorta isolation assembly, such as for example atvisualization marker (409) shown in FIG. 14B. These visualizationmarkers may be radiopaque and visible via X-ray fluoroscopy. Or, thevisualization markers may be ultrasonically visible, such as by aconstruction which is ultrasonically opaque, or by providing anultrasonic energy source which emits a signal that may located andvisualized. Furthermore, a light source may be provided as thevisualization marker. In any event, other locations than along theisolation region are contemplated for such markers, so long as theisolation region's location is readily identifiable to a user based uponvisualizing the marker. For example, according to the embodiment of FIG.14B, by removing any radiopaque marker from isolation region (430) andinflating distal and proximal balloons (420, 440) with radiopaquecontrast fluid, the balloons may provide sufficient markers in that therelatively non-radiopaque isolation region is known to be located alongthe space between them.

[0177] “Direct-Access” Endolumenal Aortic Isolation System

[0178]FIGS. 18 and 21 show endolumenal aortic isolation catheter (1800,2100) during use in a direct access endolumenal aortic isolationprocedure according to the invention. More specifically, distal endportion (1804, 2104) is shown extending into aorta (1870, 2170) throughan aperture or port (1872, 2172) that is formed along the aortic wall(1860, 2160). External valve assembly (1810, 2110) is shown after beingpositioned retrogradedly along the aorta and such that intermediateregion (1830, 2130) is aligned with a desired intervention site (1873,2173) between external valve members (1820, 1840) and (2120, 2140) wheresurgery is to be performed on the aortic wall, such as for example inorder to form a proximal anastomosis there in a coronary artery bypassprocedure. A lumen (1850, 2150) extends between port (1804, 2104) andport (1890, 2190) and across the external valve assembly (1810, 2110) inorder to allow in one mode for a proximal anastomosis procedure to beperformed while the heart is still beating and perfusing the systemicarterial circulation downstream of the proximal anastomosis site (1873).As can be seen by comparing FIGS. 18 and 21, the isolation catheter ofFIG. 21 differs from the isolation catheter of FIG. 18 in that itutilizes a movable valve (2200) with expandable region (2201)selectively positioned within lumen (1850) by advancing and retractingcannula (2204). Cannula (2204) is shown in detail in FIGS. 22A-23B anddescribed above.

[0179] Endolumenal aortic isolation catheter (1900) is shown in FIG. 19Aafter positioning external valve assembly (1910) downstream from aorticintroduction site (1972) formed in aorta (1970) and through which distalend portion of catheter (1900) is introduced into the aorta (1970).

[0180] External valve assembly (1910) is shown to include an inflatableballoon (1912) that is fluidly coupled along inflation lumen (1914) toinflation source (1914'), though other extendible members otherwiseknown or herein described may be suitable substitutes. Catheter (1900)also has an internal valve member that includes a wall (1955) that isadjustable from a first position (FIG. 19A) to a second position (FIG.19B) relative to port (1905). In the specific embodiments shown in FIGS.19A-D, wall (1955) is provided along the distal end portion of internalvalve (1950) that is slideably engaged within passageway (1951) providedalong catheter body (1902). According to this embodiment, wall (1955) isadjustable between the first and second positions by adjusting internalvalve (1950) along passageway (1951). With external balloon (1912)inflated to engage the interior wall of aorta (1970) and wall (1955) inthe first position as shown in FIG. 19A, blood from the heart and aortaupstream of port (1905) is allowed to flow through port (1905) and(1906) through distal internal lumen (1903) and antegradedly acrossexternal balloon (1912), and thereafter out into systemic arterialcirculation through distal port (1904) as shown in FIG. 19A. Byadvancing internal valve (1950) along passageway (1951), wall (1955) isadjusted to the second position to obstruct flow through ports (1905)and (1906) and thereby block fluid communication between distal internalflow lumen and the upstream region of the aorta and heart.

[0181] Further to the configuration for external valve (1910) andinternal valve (1950) as shown by reference to FIG. 19B, the heart andupstream region of the aorta are substantially isolated from thesystemic arterial circulation. The patient's systemic arterialcirculation may be supported by use of a cardiopulmonary bypass pumpwhich receives venous blood from a venous aspiration catheter and pumpsthe blood after oxygenation into the systemic arterial circulationthrough proximate internal flow lumen (1953) and out of distal port(1904).

[0182] Further variations of internal valve member (1950) are shownrespectively in FIGS. 19C-D. These variations allow for proximateinternal flow lumen (1953) to be substantially fluidly isolated fromdistal internal flow lumen (1903) and therefore also from thecardiopulmonary bypass pump while wall (1955) is in the first positionand the heart is perfusing the systemic arterial circulation throughports (1905 and 1906) and distal internal flow lumen (1903). Morespecifically to the FIG. 19C variation, internal valve member (1950) isexpandable into internal flow lumen (1953) in order to selectively openor occlude internal flow lumen (1950). According to one mode ofoperation with wall (1955) in the first position and the heart perfusingsystemic circulation through distal internal flow lumen (1903),expandable member (1955) is adjusted to the closed position tosubstantially occlude fluid communication from proximate internal flowlumen (1953). In another mode wherein wall (1955) is adjusted to thesecond position and the upstream aortic regions and heart are isolatedfrom systemic arterial circulation, expandable member (1955) is adjustedto the open position such that proximal internal flow lumen (1953)fluidly communicates with distal internal flow lumen (1903) and systemicarterial circulation may be thereby perfused by use of the by-pass pump.More detail of the specific embodiment of the internal valve member(1950) shown in FIG. 19C is shown in FIG. 19D. More specifically,internal valve member (1955) includes a wall (1957) that borderspassageway (1951) that extends along internal valve member (1950) andfluidly couples wall (1955) to a pressurizeable fluid source (notshown). By pressurizing passageway (1960), wall (1955) deflects intoproximal internal flow lumen (1953) to substantially occlude flowtherethrough. By conversely withdrawing fluid from passageway (1960) andpulling a vacuum, wall (1955) is positioned in an open position suchthat internal flow lumen (1953) is open to flow.

[0183]FIG. 20 shows a similar view of another direct access endolumenalaortic isolation system of the invention as that shown for the system ofFIG. 19A, although showing an external balloon valve having anintermediate region with a restricted outer diameter to allow for asurgical procedure to be performed on the arterial wall along thatregion. The structural features of the various individual catheterembodiments described above should not be limited to use in minimallyinvasive cardiac bypass assemblies or procedures, and may be adaptedaccording to one of ordinary skill for other medical applicationswithout departing from the scope of the present invention. Inparticular, systems which utilize one or several of the arterial andvenous embodiments described above may be used in either open heartapplications, wherein a surgeon uses the catheters provided forisolating the heart but nevertheless performs a sternotomy for directsurgical access to the heart, “port-access” types of procedures, or evenstill more minimally invasive procedures wherein the heart is isolatedby use of the catheters of the present invention and further medicaltreatment is also performed via percutaneous transluminal assemblies andmethods.

[0184] In a further example, an external shunt valve which forms ananchor and a funnel for directing flow through an internal catheterlumen, although specifically provided above in catheter embodimentswhich are adapted for shunting antegrade aortic blood flow into thesystemic arterial circulation, may also be modified for applicationswithin other lumens or body spaces and still fall within the scope ofthe present invention. Furthermore, other catheter applications thanthose described above for use in an aorta may include the internal valveembodiments herein described for selectively opening or closing aninternal flow lumen and still fall within the scope of the presentinvention.

[0185] In still a further example, catheters which are generally adaptedto isolate one body space or lumen from another body space or lumen byadjusting a valve member from a first radial position at a discretelocation around the catheter's circumference to a radially displacedposition which is adjacent to the elongate body of the catheter areconsidered within the scope of the present invention, notwithstandingthe specific description above which provides such a valve member onlyon a venous catheter in a minimally invasive cardiac bypass system.

[0186] Other modifications or combinations of the specific catheterembodiments described above which may become apparent to one of ordinaryskill from this disclosure, but which have not been specificallydescribed herein, are also contemplated as falling within the scope ofthe present invention. In addition, improvements to the embodimentswhich are not specifically provided for but which may be apparent to oneof ordinary skill based upon this disclosure are also included withinthe invention, such as for example an improvement providing a heparincoating on an external or internal surface on any one of the arterial orvenous catheter embodiments.

What is claimed is:
 1. An edolumenal aortic isolation system,comprising: an elongate body with a proximal end portion, a distal endportion, a longitudinal axis, and a flow lumen which extends between adistal port located along the distal end portion of the elongate bodyand a proximal port located along the proximal end portion of theelongate body, wherein the flow lumen communicates externally of theelongate body through an intermediate port located between the distaland proximal ports; a cannula member, having a distal and proximal endand an axis of elongation, removably and slideably carried relative tosaid elongate body so as to permit axial movement of said cannula memberwithin said flow lumen, said cannula member comprising an adjustablevalve member carried by said cannula adjacent said distal end where saidadjustable valve member is selectively positionable in said said flowlumen such that upon adjusting said adjustable valve member to a closedposition after said adjustable valve member is positioned between saidintermediate port and said proximate ports, said flow lumen is openbetween said distal and intermediate ports and closed between saidintermediate and proximate ports, and when said adjustable valve memberis adjusted to a closed position after positioning said adjustable valvemember between said distal and intermediate ports said flow lumen isopen between said proximate and intermediate ports and closed betweensaid intermediate and distal ports; an aorta isolation assembly locatedalong the distal end portion of the elongate body with a distal portionlocated proximally of the distal port, a proximal portion locatedproximally of the distal portion and distally of the intermediate port,and an intermediate region located between the distal and proximalportions, the distal and proximal portions being adjustable betweenfirst and second collapsed positions, respectively, and first and secondextended positions, also respectively, which are each adapted tocircumferentially engage an aortic wall of an aorta, wherein therespective first and second extended positions the distal and proximalportions wherein the aorta isolation assembly is adapted to isolate aproximal anastomosis site along the aortic wall from a volume ofpressurized blood at a location in the aorta either distally from thedistal portion or proximally from the proximal portion of the aortaisolation assembly with respect to the elongate body by positioning theintermediate region within the aorta along a proximal anastomosis siteand adjusting the distal and proximal portions to the first and secondextended position, respectively, to thereby engage the aortic wall onupstream and downstream sides of the proximal anastomosis site.
 2. Thesystem of claim 1 wherein said adjustable valve member comprises aninflatable balloon and said cannula member contains a pressure lumencommunicating with said inflatable balloon.
 3. The system of claim 1wherein said adjustable valve member comprises: (a) a flexiblecontainer; (b) a mass of fluid captively and sealingly contained withinsaid flexible container having a first shape to permit said flexiblecontainer to be advanced or retracted axially within said flow lumen;and (c) means carried by said cannula member and associated with saidflexible container for radial displacement of said mass of fluid to asecond position so as to occlude said flow lumen.
 4. The system of claim1, wherein the distal and proximal portions of the aorta isolationassembly are separately adjustable to the first and second extendedpositions, respectively.
 5. The system of claim 4, wherein the distaland proximal portions are adapted to couple to at least one expansionactuator and are radially expandable to the first and second extendedpositions, respectively.
 6. The system of claim 5, wherein the distaland proximal portions are adapted to couple to first and secondexpansion actuators, respectively.
 7. The system of claim 5, wherein thedistal and proximal portions comprise distal and proximal balloons,respectively, that are adapted to fluidly couple to at least onepressurizeable fluid source and to inflate to the first and secondextended positions, also respectively.
 8. The system of claim 7, whereinthe distal and proximal balloons are adapted to fluidly coupleseparately to first and second pressurizeable fluid sources,respectively.
 9. The system of claim 7, wherein the elongate bodyfurther comprises a distal inflation lumen fluidly coupled to the distalballoon and a proximal inflation lumen fluidly coupled to the proximalballoon, the distal and proximal inflation lumens being adapted tofluidly couple to said at least one pressurizeable fluid source.
 10. Thesystem of claim 7, wherein the distal and proximal inflation lumens areadapted to separately couple to first and second pressurizeable fluidsources, respectively.
 11. The system of claim 5, wherein the distal andproximal portions are adapted to couple to a common expansion actuatorwhich is adjustable between first and second actuating conditions, thedistal portion being expandable to the first extended position when thecommon actuator is adjustable to the first actuating condition, and theproximal portion being adjustable to the second extended position whenthe common actuator is adjusted to the second actuating condition. 12.The system of claim 11, wherein the distal and proximal portionscomprise distal and proximal balloons, respectively, which are eachadapted to fluidly couple to a common pressurizeable fluid source andare inflatable with fluid from the fluid source to the first and secondextended positions, respectively, wherein the distal balloon isinflatable to the first extended position when the fluid is adjusted toa first pressure, and wherein the proximal balloon is inflatable to thesecond extended position when the fluid is adjusted to a secondpressure.
 13. The system of claim 12, wherein the distal ballooncomprises a first material with a first compliance and the proximalballoon comprises a second material with a second compliance which isdifferent from the first compliance.
 14. The system of claim 12, theelongate body further comprises a common lumen which is fluidly coupledto the distal and proximal balloons and which is also adapted to coupleto the common pressurizeable source of fluid.
 15. The system of claim 1,wherein the distal and proximal portions are adjustable together to thefirst and second extended positions, respectively.
 16. The system ofclaim 15, wherein the distal and proximal portions are adapted to coupleto a common actuator which adjusts the distal and proximal portionstogether to the first and second extended positions.
 17. The system ofclaim 16, wherein the distal and proximal portions comprise distal andproximal regions, respectively, of a balloon and the intermediate regionof the aorta isolation assembly is located between the distal andproximal regions wherein the balloon is adapted to fluidly couple to apressurizeable fluid source and to inflate with fluid from the fluidsource to a radially expanded condition which characterizes the firstand second positions for the distal and proximal portions, respectively.18. The system of claim 17, wherein in the radially expanded conditionthe distal and proximal regions are expanded with first and secondexpanded outer diameters, respectively, which are sufficient to radiallyengage the aortic wall, and the intermediate region is expanded with athird expanded outer diameter that is less than the first and secondexpanded outer diameters and that is insufficient to radially engage theaortic wall along the proximal anastomosis site.
 19. The system of claim18, wherein the distal and proximal regions of the inflatable balloonare constructed to exhibit first and second radial compliances,respectively, when the balloon is being inflated; and the balloon alongthe intermediate region is constructed to exhibit a third radialcompliance that is less than the first and second radial complianceswhen the balloon is being inflated.
 20. The system of claim 19, whereinthe balloon along the intermediate region comprises a different materialthan at least one of the distal and proximal regions of the balloon. 21.The system of claim 19, wherein the balloon comprises a balloon skinconstructed at least in part of a material which extends along theintermediate region and at least one of the distal and proximal regions,wherein the balloon skin along the intermediate region has a first wallthickness and along the at least one of the distal and proximal regionshas a second wall thickness which is less than the first wall thickness.22. The system of claim 18, wherein an expansion limiter is providedalong the intermediate region and which limits the expansion of theballoon along the intermediate region to the third expanded outerdiameter in the radially expanded condition.
 23. The system of claim 22,wherein the balloon along the intermediate region comprises a firstmaterial; and the expansion limiter comprises a second material whichcovers the first material.
 24. The system of claim 22, wherein theballoon along the intermediate region comprises a first material; andthe expansion limiter comprises a second material which forms acomposite with the first material.
 25. The system of claim 24, whereinthe balloon along the intermediate region comprises a first material;and the expansion limiter comprises a second material which is embeddedwithin the first material.
 26. The system of claim 24, wherein theballoon along the intermediate region comprises a first material; andthe expansion limiter comprises a second material which is laminatedwith the first material.
 27. The system of claim 18, wherein the distalportion is constructed to exhibit a first compliance when the balloon isinflated; and the proximal portion is constructed to exhibit a secondcompliance when the balloon is inflated that is substantially differentthan the first compliance such that the distal and proximal regionsexpand to the first and second extended positions, respectively, atdifferent inflation pressures, whereby controlling the inflationpressure of the balloon the distal and proximal portions may becontrollably and sequentially engaged to the aortic wall.
 28. The systemof claim 1, wherein the intermediate port comprises a plurality ofapertures through which the flow lumen communicates externally of theelongate body.
 29. The system of claim 1, further comprising avisualization marker provided as a predetermined location relative tothe intermediate region, such that the visualization marker and therebythe intermediate region may be located from a position externally of theaorta prior to forming the proximal anastomosis at the proximalanastomosis site.
 30. The system of claim 29, wherein the visualizationmarker comprises a radiopaque material which is visible via X-rayfluoroscopy.
 31. The system of claim 29, wherein the visualizationmarker is ultrasonically visible.
 32. The system of claim 31, furthercomprising an ultrasound imaging system which is adapted toultrasonically locate the visualization marker from a locationexternally of the aorta when the visualization marker is positionedwithin the aorta.
 33. The system of claim 29, wherein the visualizationmarker comprises a light source which is adapted to emit light fromwithin the aorta that which is detectable from a location externally ofthe aorta.
 34. The system of claim 1, wherein the first and secondextended positions, the distal and proximal portions are substantiallyradiopaque and visible using X-ray fluoroscopy, and the intermediateregion is substantially non-radiopaque, such that the location of theintermediate region within the aorta may be identified under X-rayfluoroscopy in relation to the respectively spaced locations of theradiopaque distal and proximal portions.
 35. The system of claim 1,further comprising: a proximal anastomosis device assembly which isadapted to anastomose a proximal end of a bypass graft to an apertureformed in the aortic wall at the proximal anastomosis site.
 36. Thesystem of claim 1, further comprising: a distal anastomosis deviceassembly which is adapted to anastomose a distal end of a bypass graftto an aperture formed in an arterial wall at a distal anastomosis site.37. The system of claim 1, further comprising: a support assembly whichis adapted to engage a heart of the patient and to secure the heart suchthat at least one of a proximal anastomosis along the proximalanastomosis site and a distal anastomosis along a distal anastomosissite of a cardiac artery may be formed with an arterial by-pass graftwhile the heart is beating.
 38. The system of claim 1, furthercomprising: at least one actuator which is adapted to couple to andadjust at least one of the distal and proximal portions to therespectively extended position.
 39. The system of claim 1, furthercomprising: a venting member with a proximal end portion, a distal endportion, and a venting lumen which extends between a distal venting portalong the distal end portion of the venting member and a proximalventing port along the proximal end portion of the venting member,wherein the distal end portion of the venting member is adapted to bepositioned upstream from the proximal anastomosis site with the proximalend portion of the venting member positioned externally of the patientwhen the intermediate region is positioned along the proximalanastomosis site.
 40. The system of claim 39, further comprising: adecompression pump which is adapted to couple to the proximal ventingport externally of the patient.
 41. The system of claim 1, furthercomprising: a cardioplegia member with a proximal end portion, a distalend portion, and a cardioplegia lumen which extends between a distalcardioplegia port along the distal end portion of the cardioplegiamember and a proximal cardioplegia port along the proximal end portionof the cardioplegia member, wherein the distal end portion of thecardioplegia member is adapted to be positioned upstream from theproximal anastomosis site with the proximal end portion of thecardioplegia member positioned externally of the patient when theisolation region is positioned along the proximal anastomosis site. 42.The system of claim 1, further comprising: a cardiac bypass pumpassembly which is adapted to couple to the proximal port and also tocirculate oxygenated blood into the flow lumen through the proximalport, such that by adjusting said adjustable valve to the closedposition the oxygenated blood may be delivered to the patient from theproximal port, along the flow lumen, and through the intermediate port.43. A method for anastomosing an arterial bypass graft to a proximalanastomosis site along an aortic wall of an aorta in a patient,comprising: endolumenally isolating a proximal anastomosis site along anaortic wall from a volume of pressurized blood in the aorta using anaorta isolation assembly provided along a distal end portion of thebody; said elongate body having a proximal end portion, a distal endportion, a longitudinal axis, and a flow lumen which extends between adistal port located along the distal end portion of the elongate bodyand a proximal port located along the proximal end portion of theelongate body, wherein the flow lumen communicates externally of theelongate body through an intermediate port located between the distaland proximal ports; while the proximal anastomosis site is isolated fromthe volume of pressurized blood with the aorta isolation assembly,shunting the volume of blood through said flow lumen along the elongatebody from such distal port of the flow lumen positioned along anupstream region of the aorta located upstream from the proximalanastomosis site and through a proximal port of the flow lumenpositioned along a downstream region of the aorta located downstreamfrom the proximal anastomosis site; and while the volume of blood isbeing shunted from the upstream region to the downstream region,positioning a movable cannula having an adjustable valve within the flowlumen between the distal and proximal ports and expanding saidadjustable valve within the flow lumen proximally of said intermediateport to a closed position.
 44. The method of claim 43, furthercomprising while the proximal anastomosis site is being isolated fromthe volume of pressurized blood, and while the volume of pressurizedblood is being shunted from the upstream region to the downstream regionof the aorta, forming a proximal anastomosis between the arterial bypassgraft and the proximal anastomosis site.
 45. The method of claim 44,further comprising isolating the proximal anastomosis site in a “beatingheart” coronary bypass graft procedure.
 46. The method of claim 44,further comprising isolating the proximal anastomosis site in a“semi-beating heart” coronary artery bypass graft procedure.
 47. Anendolumenal aortic isolation system for use in an endolumenal aorticisolation procedure along an aorta of a patient comprising: an elongatebody with a proximal end portion and a distal end portion, wherein thedistal end portion is adapted to be positioned within the aorta with theproximal end portion extending externally of the aorta; a first flowpassageway which in the shunting position extends along the distal endportion between a first port and a second port; a second flow passagewayextending along the elongate body between the first port and a thirdport located along the proximal end portion; and a flow valve systemwhich is adjustable between a first condition and a second condition,wherein in the first condition the flow valve system is adapted to allowfluid communication along the first flow passageway between a firstlocation externally adjacent the first port relative to the first flowpassageway and a second location externally adjacent the first portrelative to the first flow passageway and a second location externallyadjacent the second port relative to the first flow passageway, and alsoto substantially fluidly isolate the first location from a thirdlocation externally adjacent the third port relative to the secondpassageway, and wherein in the second condition the flow valve system isadapted to allow fluid communication along the second flow passagewayand between the first location and the third location, and also tosubstantially fluidly isolate the first location from the secondlocation relative to the first flow passageway.
 48. The system of claim47, further comprising: an external valve located along the distal endportion between the first and second ports and which is adjustablebetween an open position and a shunting position, wherein in the openposition the distal end portion is adapted to be positioned within theaorta with the external valve at a predetermined location such that inthe shunting position the external valve is adapted to isolate bloodfrom flowing between the first and second ports and across thepredetermined location within the aorta other than through the firstflow passageway.
 49. The system of claim 48, wherein the external valvecomprises an inflatable balloon which is adapted to be fluidly coupledto a pressurizeable source of fluid.
 50. The system of claim 47, whereinthe first port is located distally of the second port along the distalend portion.
 51. The system of claim 47, wherein the first port islocated proximally of the second port along the distal end portion. 52.The system of claim 47, wherein the flow valve assembly comprises: afirst flow valve assembly with a first flow valve coupled to the firstflow passageway and which is adjustable between an open position, whichis adapted to allow the first and second locations to fluidlycommunicate through the first and second ports and along the first flowpassageway, and a closed position, which is adapted to substantiallyfluidly isolate the first and second locations relative to the first andsecond ports and first flow passageway; and a second flow valve assemblywith a second flow valve coupled to the second flow passageway and whichis adjustable between an open position, which is adapted to allow thefirst and third locations to fluidly communicate through the first andthird ports and along the second flow passageway, and a closed position,which is adapted to substantially fluidly isolate the first and thirdlocations relative to the first and third ports and second flowpassageway, wherein the first condition is characterized at least inpart by the open position for the first flow valve and the closedposition for the second flow valve, and the second condition ischaracterized at least in part by the closed position for the first flowvalve and the open position for the second flow valve.
 53. The system ofclaim 52, wherein the first flow valve comprises a wall having anadjustable location between the open and closed positions for the firstflow valve, wherein in the open position for the first flow valve thewall is located to allow for the fluid communication between the firstand second locations, and wherein in the closed position for the firstflow valve the wall is located to substantially block the fluidcommunication between the first and second locations relative to thefirst and second ports and first flow passageway.
 54. The system ofclaim 53, wherein in the closed position for the first flow valve thewall is located to substantially block the second port.
 55. The systemof claim 53, wherein the first flow valve assembly further comprises anactuating member with a distal end portion coupled to the wall and aproximal end portion extending along the proximal end portion of theelongate body, wherein the location of the wall with respect to the openand closed positions for the first flow valve is adjustable bymechanical manipulation of the actuating member.
 56. The system of claim52, wherein the second flow valve comprises a wall having an adjustablelocation between the open and closed positions for the second flowvalve, wherein in the open position for the second flow valve the wallis located to allow for the fluid communication between the first andthird locations, and wherein in the closed position for the second flowvalve the wall is located to substantially block the fluid communicationbetween the first and third locations relative to the first and thirdports and second flow passageway.
 57. The system of claim 52, whereinthe first and second flow valves are adapted to be independentlyadjusted to their respective open and closed positions.
 58. The systemof claim 47, wherein the flow valve assembly comprises: a first wallthat is adjustable between an open position, which is located to allowfor the fluid communication between the first and second location, and aclosed position which is located to substantially block the fluidcommunication between the first and second locations relative to thefirst and second ports and first flow passageway; and a second wall thatis adjustable between an open position, which is located to allow forthe fluid communication between the first and third locations, and aclosed position, which is located to substantially block the fluidcommunication between the first and third locations relative to thefirst and third ports and second flow passageway, wherein the firstcondition is characterized at least in part by the first wall in theopen position and the second wall in the closed position, and the secondcondition is characterized at least in part by the first wall in theclosed position and the second wall in the open position.
 59. The systemof claim 58, wherein the first and second walls are adapted to beseparately and independently adjusted to their respective open andclosed positions.
 60. The system of claim 58, wherein the first andsecond walls are adapted to be adjusted to their respective open andclosed positions together.
 61. The system of claim 47, wherein the flowvalve system comprises a single valve member which is coupled to thefirst and second flow passageways and is adjustable between first andsecond positions which characterize at least in part the first andsecond conditions, respectively, for the flow valve assembly.
 62. Thesystem of claim 47, wherein the distal end portion further comprises acommon passageway which communicates externally of the distal endportion through the first port, wherein each of the first and secondflow passageways are formed at least in part by the common passageway.63. A method for endolumenally isolating a region of an aorta,comprising introducing a distal end portion of an endolumenal aorticisolation catheter through an introduction site along an aortic wall ofthe aorta; positioning the endolumenal aortic isolation catheter suchthat first and second ports and a first flow passageway extendingtherebetween along the distal end portion are located upstream of anaortic arch of the aorta, and further such that a proximal end portionof the catheter extends externally of the introduction site.
 64. Themethod of claim 63, further comprising: introducing the distal endportion through the introduction site located along the ascending aorta;and positioning the distal end portion within the aorta downstream ofthe introduction site.